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From [link] , find the number of towns that have rainfall between 2.95 and 9.01 inches.

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6 + 7 + 15 = 28 towns

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Collaborative exercise

In your class, have someone conduct a survey of the number of siblings (brothers and sisters) each student has. Create a frequency table. Add to it a relative frequency column and a cumulative relative frequency column. Answer the following questions:

  1. What percentage of the students in your class have no siblings?
  2. What percentage of the students have from one to three siblings?
  3. What percentage of the students have fewer than three siblings?

Nineteen people were asked how many miles, to the nearest mile, they commute to work each day. The data are as follows:

  • 2
  • 5
  • 7
  • 3
  • 2
  • 10
  • 18
  • 15
  • 20
  • 7
  • 10
  • 18
  • 5
  • 12
  • 13
  • 12
  • 4
  • 5
  • 10
. [link] was produced:

Frequency of commuting distances
3 3 3 19 0.1579
4 1 1 19 0.2105
5 3 3 19 0.1579
7 2 2 19 0.2632
10 3 4 19 0.4737
12 2 2 19 0.7895
13 1 1 19 0.8421
15 1 1 19 0.8948
18 1 1 19 0.9474
20 1 1 19 1.0000
  1. Is the table correct? If it is not correct, what is wrong?
  2. True or False: Three percent of the people surveyed commute three miles. If the statement is not correct, what should it be? If the table is incorrect, make the corrections.
  3. What fraction of the people surveyed commute five or seven miles?
  4. What fraction of the people surveyed commute 12 miles or more? Less than 12 miles? Between five and 13 miles (not including five and 13 miles)?
  1. No. The frequency column sums to 18, not 19. Not all cumulative relative frequencies are correct.
  2. False. The frequency for three miles should be one; for two miles (left out), two. The cumulative relative frequency column should read: 0.1052, 0.1579, 0.2105, 0.3684, 0.4737, 0.6316, 0.7368, 0.7895, 0.8421, 0.9474, 1.0000.
  3. 5 19
  4. 7 19 , 12 19 , 7 19
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[link] represents the amount, in inches, of annual rainfall in a sample of towns. What fraction of towns surveyed get between 11.03 and 13.05 inches of rainfall each year?

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9 50

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[link] contains the total number of deaths worldwide as a result of earthquakes for the period from 2000 to 2012.

Year Total Number of Deaths
2000 231
2001 21,357
2002 11,685
2003 33,819
2004 228,802
2005 88,003
2006 6,605
2007 712
2008 88,011
2009 1,790
2010 320,120
2011 21,953
2012 768
Total 823,356

Answer the following questions.

  1. What is the frequency of deaths measured from 2006 through 2009?
  2. What percentage of deaths occurred after 2009?
  3. What is the relative frequency of deaths that occurred in 2003 or earlier?
  4. What is the percentage of deaths that occurred in 2004?
  5. What kind of data are the numbers of deaths?
  6. The Richter scale is used to quantify the energy produced by an earthquake. Examples of Richter scale numbers are 2.3, 4.0, 6.1, and 7.0. What kind of data are these numbers?
  1. 97,118 (11.8%)
  2. 41.6%
  3. 67,092/823,356 or 0.081 or 8.1 %
  4. 27.8%
  5. Quantitative discrete
  6. Quantitative continuous
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[link] contains the total number of fatal motor vehicle traffic crashes in the United States for the period from 1994 to 2011.

Year Total Number of Crashes Year Total Number of Crashes
1994 36,254 2004 38,444
1995 37,241 2005 39,252
1996 37,494 2006 38,648
1997 37,324 2007 37,435
1998 37,107 2008 34,172
1999 37,140 2009 30,862
2000 37,526 2010 30,296
2001 37,862 2011 29,757
2002 38,491 Total 653,782
2003 38,477

Answer the following questions.

  1. What is the frequency of deaths measured from 2000 through 2004?
  2. What percentage of deaths occurred after 2006?
  3. What is the relative frequency of deaths that occurred in 2000 or before?
  4. What is the percentage of deaths that occurred in 2011?
  5. What is the cumulative relative frequency for 2006? Explain what this number tells you about the data.

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  1. 190,800 (29.2%)
  2. 24.9%
  3. 260,086/653,782 or 39.8%
  4. 4.6%
  5. 75.1% of all fatal traffic crashes for the period from 1994 to 2011 happened from 1994 to 2006.
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“State&County QuickFacts,” U.S. Census Bureau. http://quickfacts.census.gov/qfd/download_data.html (accessed May 1, 2013).

“State&County QuickFacts: Quick, easy access to facts about people, business, and geography,” U.S. Census Bureau. http://quickfacts.census.gov/qfd/index.html (accessed May 1, 2013).

“Table 5: Direct hits by mainland United States Hurricanes (1851-2004),” National Hurricane Center, http://www.nhc.noaa.gov/gifs/table5.gif (accessed May 1, 2013).

“Levels of Measurement,” http://infinity.cos.edu/faculty/woodbury/stats/tutorial/Data_Levels.htm (accessed May 1, 2013).

Courtney Taylor, “Levels of Measurement,” about.com, http://statistics.about.com/od/HelpandTutorials/a/Levels-Of-Measurement.htm (accessed May 1, 2013).

David Lane. “Levels of Measurement,” Connexions, http://cnx.org/content/m10809/latest/ (accessed May 1, 2013).

Chapter review

Some calculations generate numbers that are artificially precise. It is not necessary to report a value to eight decimal places when the measures that generated that value were only accurate to the nearest tenth. Round off your final answer to one more decimal place than was present in the original data. This means that if you have data measured to the nearest tenth of a unit, report the final statistic to the nearest hundredth.

In addition to rounding your answers, you can measure your data using the following four levels of measurement.

  • Nominal scale level: data that cannot be ordered nor can it be used in calculations
  • Ordinal scale level: data that can be ordered; the differences cannot be measured
  • Interval scale level: data with a definite ordering but no starting point; the differences can be measured, but there is no such thing as a ratio.
  • Ratio scale level: data with a starting point that can be ordered; the differences have meaning and ratios can be calculated.

When organizing data, it is important to know how many times a value appears. How many statistics students study five hours or more for an exam? What percent of families on our block own two pets? Frequency, relative frequency, and cumulative relative frequency are measures that answer questions like these.

What type of measure scale is being used? Nominal, ordinal, interval or ratio.

  1. High school soccer players classified by their athletic ability: Superior, Average, Above average
  2. Baking temperatures for various main dishes: 350, 400, 325, 250, 300
  3. The colors of crayons in a 24-crayon box
  4. Social security numbers
  5. Incomes measured in dollars
  6. A satisfaction survey of a social website by number: 1 = very satisfied, 2 = somewhat satisfied, 3 = not satisfied
  7. Political outlook: extreme left, left-of-center, right-of-center, extreme right
  8. Time of day on an analog watch
  9. The distance in miles to the closest grocery store
  10. The dates 1066, 1492, 1644, 1947, and 1944
  11. The heights of 21–65 year-old women
  12. Common letter grades: A, B, C, D, and F
  1. ordinal
  2. interval
  3. nominal
  4. nominal
  5. ratio
  6. ordinal
  7. nominal
  8. interval
  9. ratio
  10. interval
  11. ratio
  12. ordinal
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Questions & Answers

only asking what is hospital statistics
Suly Reply
What's the meaning Of statistic
Farouk Reply
The mean is the average of the numbers. It is easy to calculate: add up all the numbers, then divide by how many numbers there are. In other words it is the sum divided by the count.
khama Reply
pls I want to know the characterize of mean
Trixie Reply
I want solution to; x,x+1,3.5,3.4 and 2.5 is 3.1. find the value of x
mean is nothing but average.
(x+x+1+3.5+3.4+2.5)/5=3.1 2x+10.4=3.1*5 x=(15.5-10.4)/2 x=2.55
How. Pls explain or break it down thanks
the sum of all five divided by the 5 which is the average is equal to 3.1 so you sum them, divide and equate to 3.1. then solve for X by making X the subject
Think of it as your grade, or gpa. how do you find the average of it?
nicely explained
What is the meaning of statistics and it's relevance in the social sciences
Icecool Reply
statistics is the branch of mathematics that using math& statistics theories to interpret data to information which is supporting the decision makers in social sciences and applied too. statistics is decision making science now aday
I want to slove this math
Enny Reply
I'm not seeing the Math problem?
the data below where from 1 miles. miles 1:8380, 8210,3836,7840,7910,7510,7720,7750,8100,7690 test wherever their difference is significance at 5% level with population of #8000.
me too
enny i don't see any math problems
hello my friend. how can you help me to solve math
help me the interquartile range and semi interquartile range of grouped data
what is the difference between macro and micro data?
Sani Reply
Macrodata consist of 'headcounts', Microdata contain data on individuals,
macro is a big business and micro is small business
macro means whole or big and micro means part or small therefore in relation to data, macro data will be big or whole data and micro data will be small or individual part of a data. for example taking the whole data of an organisation or economy that will be macro data and taking the data on employe
employees will be micro data
How to determine appropriate statistics tool for my data
Jayr Reply
You cannot know everything! Statistics is a vast subject so don’t be afraid to say that you don’t know. Ask others for help or look up information on the internet to help. Don’t assume that the student knows anything about the technique they are suggesting!
my class starts at February 4th
P is the probability that a given die shows even number. To test H0 : P =1/2 against H1 : P=1/3, following procedure is adopted. Toss the die twice and accept H0 if both times it shows even number. Find the probabilities of type I and type II errors
Loyolite Reply
what is statistics?
bilal Reply
what is data
It Is the collection, collation,Analysing Interpretation,and presentation of data....
statistics is a science that studies numerical values assigned to objects, attributes or variables in order to characterize and make the variables more meaningful.
statistics is the science of collection, analysis, Interpretation & presentation of numerical data
Numeric data
if you think about normal number and operations of math such as fractions and percent values, statisitics is when it comes down to it a lot of just that - counting and then fractions, then that data and those counts (and ratios)/fractions that were used or counted in one group will represent a pop.
An example is, lets say you are in charge of making large orders of supplies and that based on your need of X bricks = X feet of building - now thats the math, well stats is using that math in a way the next person making orders can base those orders of what they will need based on saying "in this
..case, when Bilal needed 75 feet of building walls that 150 bricks were used" - now, that helps to get one job done but if we then watch those jobs one at a time, and count that 5/5 times the count was 150 bricks total - the new person could order 150 bricks with a high probability of being right
If X is a Uniform random variable in [ -2, 2 ], find the pdf of Y X  and E Y[ ].
Kezang Reply
could you resend the question it is not clear after " the PDF of---" ?
ap kis year ki student ho
Mastrs ist year
I'm from 2nd year BHU
ap kis year ki student ho
I'm student of bs(hons) 1st year
tell me good definition of statistics?
I want to know statistics
Okosa Reply
why is data so important in statistics
Trixie Reply
want summary statistic on gender, age group, weight, and weight loss
are you asking question or looking for Solution
solution pls
1st convert gender and group to factor than use summary function It will give mean median and mode with other details
its a bit complicated could u bring it to my level of under standing
u know the question was put in a tabular form where we were to find the variable type, summary statistics and graph type of the given variables that's the gender,age group, weight and weight loss
if you see, gender and group are not numerical due to which they will not give you correct statistics
how you denote gender m or f
or t
ok tnk u
these are not numerical so you have to convert they as f=1; m=2; t=3 same thing you have to do with group or any variable which is character else you should drop them
from your calculation
oh OK tnk u
so pls why is data important in statistics
not only data correct data is imp
statistics works on data only
without data you can not summarize, can not predict future, can not establish relationship between two and more variables, can not prepare reports and make decisions on it
so I'll give example. suppose you want to open a restaurant and you have to choose one best location out of 5. then how you will decide which location is best for you
awww thank you pls
pls I want a brief note on observation, survey and experimentation way of obtaining data
please Tell me difference parameters and non parameter
can you tell me about the scopes of statistics?
plzzz answer me anyone .
Methods of Collecting Data Observation Observational studies allow researchers to document behavior in a natural setting and witness events that could not be produced in a lab.
Key Points Observation differs from most other forms of data collection in that the researcher does not manipulate variables or directly question participants. The advantages of observation include observing natural behavior, refining hypotheses, and allowing for observation of behavior that canno
 be produced in an artificial environment for ethical or practical reasons. The disadvantages of observation are that these studies do not produce quantitative data, do not allow for cause and effect statements, may be very time consuming, and can be prone to researcher bias.
Key Terms observational research: Research focusing on the observation of behavior outside of a laboratory setting. external validity: In research, whether or not study findings can be generalized to real world scenarios.
Surveys and Interviews Surveys are a low-cost option for gathering a large amount of data, but they are also susceptible to reporting bias.
Key Points The survey method of data collection is likely the most common of the four major research methods. The benefits of this method include low cost, large sample size, and efficiency.
The major problem with this method is accuracy: since surveys depend on subjects’ motivation, honesty, memory, and ability to respond, they are very susceptible to bias. A researcher must have a strong understanding of how to properly frame survey questions in order to gather reliable and relevant
Key Terms reliability: The degree to which a measure is likely to yield consistent results each time it is used. validity: The degree to which a measure is actually assessing the concept it was designed to measure. survey: A method for collecting qualitative and quantitative information about ind
individuals in a population.
Interviews Interviews are a type of qualitative data in which the researcher asks questions to elicit facts or statements from the interviewee. Interviews used for research can take several forms:
Informal Interview: A more conversational type of interview, no questions are asked and the interviewee is allowed to talk freely. General interview guide approach: Ensures that the same general areas of information are collected from each interviewee. Provides more focus than the conversational ap
approach, but still allows a degree of freedom and adaptability in getting the information from the interviewee. Standardized, open-ended interview: The same open-ended questions are asked to all interviewees. This approach facilitates faster interviews that can be more easily analyzed and compared
Closed, fixed-response interview (Structured): All interviewees are asked the same questions and asked to choose answers from among the same set of alternatives.
experiments An experiment involves the creation of a contrived situation in order that the researcher can manipulate one or more variables whilst controlling all of the others and measuring the resultant effects.
Boyd and Westfall1 have defined experimentation as: "...that research process in which one or more variables are manipulated under conditions which permit the collection of data which show the effects, if any, in unconfused fashion."
Experiments can be conducted either in the field or in a laboratory setting. When operating within a laboratory environment, the researcher has direct control over most, if not all, of the variables that could impact upon the outcome of the experiment
When experiments are conducted within a natural setting then they are termed field experiments. The variety test carried out by United Fruits on their Gros Michel and Valery bananas is an example of a field experiment.
parameter Parameters are factors or limits which affect the way that something can be done or made
Minhal didny get your question, can you please elaborate more
pls can u use mean n mode at the statistical summary pls
yes, statistical summary itself gives all value
but u didn't tell me the advantage and disadvantage of the experimental method
but you didn't tell me the advantage and disadvantage of experimental method
tell me to make a hosrogram of dicrete values
by using a sampling distribution? how to estimate the population mean using a ramdom variable n?
Jade Reply
what is the important of statistics
The “average increase” for all NASDAQ stocks is the:
da Reply

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Source:  OpenStax, Introductory statistics. OpenStax CNX. May 06, 2016 Download for free at http://legacy.cnx.org/content/col11562/1.18
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