<< Chapter < Page
  Introductory statistics     Page 21 / 36
Chapter >> Page >

78 . For a chi-square distribution with five degrees of freedom, the curve is ______________.

11.3: test of independence

Use the following information to answer the next four exercises. You are considering conducting a chi-square test of independence for the data in this table, which displays data about cell phone ownership for freshman and seniors at a high school. Your null hypothesis is that cell phone ownership is independent of class standing.

79 . Compute the expected values for the cells.

Cell = Yes Cell = No
Freshman 100 150
Senior 200 50

80 . Compute ( O E ) 2 z for each cell, where O = observed and E = expected.

81 . What is the chi-square statistic and degrees of freedom for this study?

82 . At the α = 0.5 significance level, what is your decision regarding the null hypothesis?

11.4: test of homogeneity

83 . You conduct a chi-square test of homogeneity for data in a five by two table. What is the degrees of freedom for this test?

11.5: comparison summary of the chi-square tests: goodness-of-fit, independence and homogeneity

84 . A 2013 poll in the State of California surveyed people about taxing sugar-sweetened beverages. The results are presented in the following table, and are classified by ethnic group and response type. Are the poll responses independent of the participants’ ethnic group? Conduct a hypothesis test at the 5% significance level.

Ethnic Group \ Response Type Favor Oppose No Opinion Row Total
White / Non-Hispanic 234 433 43 710
Latino 147 106 19 272
African American 24 41 6 71
Asian American 54 48 16 118
Column Total 459 628 84 1171

85 . In a test of homogeneity, what must be true about the expected value of each cell?

86 . Stated in general terms, what are the null and alternative hypotheses for the chi-square test of independence?

87 . Stated in general terms, what are the null and alternative hypotheses for the chi-square test of homogeneity?

11.6: test of a single variance

88 . A lab test claims to have a variance of no more than five. You believe the variance is greater. What are the null and alternative hypothesis to test this?

Practice test 3 solutions

8.1: confidence interval, single population mean, population standard deviation known, normal

1 . σ n = 4 30 = 0.73

2 . normal

3 . 0.025 or 2.5%; A 95% confidence interval contains 95% of the probability, and excludes five percent, and the five percent excluded is split evenly between the upper and lower tails of the distribution.

4 . z -score = 1.96; E B M =   z α 2 ( σ n ) = ( 1.96 ) ( 0.73 ) =   1.4308

5 . 41 ± 1.43 = (39.57, 42.43); Using the calculator function Zinterval, answer is (40.74, 41.26. Answers differ due to rounding.

6 . The z -value for a 90% confidence interval is 1.645, so EBM = 1.645(0.73) = 1.20085.
The 90% confidence interval is 41 ± 1.20 = (39.80, 42.20).
The calculator function Zinterval answer is (40.78, 41.23). Answers differ due to rounding.

7 . The standard error of measurement is: σ n =   4 50 = 0.57
E B M =   z α 2 ( σ n ) = ( 1.96 ) ( 0.57 ) =   1.12
The 95% confidence interval is 41 ± 1.12 = (39.88, 42.12).
The calculator function Zinterval answer is (40.84, 41.16). Answers differ due to rounding.

Questions & Answers

the probability of an event occuring is defined as?
James Reply
The probability of an even occurring is expected event÷ event being cancelled or event occurring / event not occurring
what is simple bar chat
Toyin Reply
Simple Bar Chart is a Diagram which shows the data values in form of horizontal bars. It shows categories along y-axis and values along x-axis. The x-axis displays above the bars and y-axis displays on left of the bars with the bars extending to the right side according to their values.
statistics is percentage only
Moha Reply
the first word is chance for that we use percentages
it is not at all that statistics is a percentage only
I need more examples
Luwam Reply
how to calculate sample needed
Jim Reply
mole of sample/mole ratio or Va Vb
how to I solve for arithmetic mean
Joe Reply
Yeah. for you to say.
how do I solve for arithmetic mean
Joe Reply
please answer these questions
add all the data and divide by the number of data sets. For example, if test scores were 70, 60, 70, 80 the total is 280 and the total data sets referred to as N is 4. Therfore the mean or arthritmatic average is 70. I hope this helps.
*Tan A - Tan B = sin(A-B)/CosA CosB ... *2sinQ/Cos 3Q = tan 3Q - tan Q
Ibraheem Reply
standard error of sample
Umar Reply
what is subjective probability
Avela Reply
how to calculate the Steadman rank correlation
what is sampling? i want to know about the definition of sampling.
anup Reply
what is sample...?
Abdul Reply
In terms of Statistics or Research , It is a subset of population for measurement.
can you solve this problem
Gayanne Reply
which problem
what is the meaning of correlation ratio?
in 2018,walewale hospital recorded 2500cases of infection it was seen that out of this number 350 cases are rti 150 were bronchitis 300 cases were otitis media the rest were peptic ulcer cases calculate proportion of peptic ulcer and percentage of bronchitis
Ayana Reply
what is statistics
what is the frequency
okoh Reply
Frequency is the number of all object which is comes from population or sample size
Denoted by f
number of all objects?
frequency is the rate of occurrence of an object
Explain nominal and ordinal variables
 nominal variables are those variable which is used to “name,” a series of values.
while  ordinal scales provide good information about the order of choices,for example in a customer satisfaction survey.
what is the difference between Mean and Varience?
Sum of total object, divided by number of object is called mean
faiqa U didn't clear me.Sorry
what is df in statistics
degre of freedom

Get the best Introductory statistics course in your pocket!

Source:  OpenStax, Introductory statistics. OpenStax CNX. May 06, 2016 Download for free at http://legacy.cnx.org/content/col11562/1.18
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Introductory statistics' conversation and receive update notifications?