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41 . As the degrees of freedom increase in an F distribution, the distribution becomes more nearly normal. Histogram F 2 is closer to a normal distribution than histogram F 1, so the sample displayed in histogram F 1 was drawn from the F 3,15 population, and the sample displayed in histogram F 2 was drawn from the F 5,500 population.

42 . Using the calculator function Fcdf, p -value = Fcdf(3.67, 1E, 3,50) = 0.0182. Reject the null hypothesis.

43 . Using the calculator function Fcdf, p -value = Fcdf(4.72, 1E, 4, 100) = 0.0016 Reject the null hypothesis.

13.4: test of two variances

44 . The samples must be drawn from populations that are normally distributed, and must be drawn from independent populations.

45 . Let σ M 2 = variance in math grades, and σ E 2 = variance in English grades.
H 0 : σ M 2 σ E 2
H a : σ M 2 > σ E 2

Practice final exam 1

Use the following information to answer the next two exercises: An experiment consists of tossing two, 12-sided dice (the numbers 1–12 are printed on the sides of each die).

  • Let Event A = both dice show an even number.
  • Let Event B = both dice show a number more than eight

1 . Events A and B are:

  1. mutually exclusive.
  2. independent.
  3. mutually exclusive and independent.
  4. neither mutually exclusive nor independent.

2 . Find P ( A | B ).

  1. 2 4
  2. 16 144
  3. 4 16
  4. 2 144

3 . Which of the following are TRUE when we perform a hypothesis test on matched or paired samples?

  1. Sample sizes are almost never small.
  2. Two measurements are drawn from the same pair of individuals or objects.
  3. Two sample means are compared to each other.
  4. Answer choices b and c are both true.


Use the following information to answer the next two exercises: One hundred eighteen students were asked what type of color their bedrooms were painted: light colors, dark colors, or vibrant colors. The results were tabulated according to gender.

Light colors Dark colors Vibrant colors
Female 20 22 28
Male 10 30 8

4 . Find the probability that a randomly chosen student is male or has a bedroom painted with light colors.

  1. 10 118
  2. 68 118
  3. 48 118
  4. 10 48

5 . Find the probability that a randomly chosen student is male given the student’s bedroom is painted with dark colors.

  1. 30 118
  2. 30 48
  3. 22 118
  4. 30 52


Use the following information to answer the next two exercises: We are interested in the number of times a teenager must be reminded to do his or her chores each week. A survey of 40 mothers was conducted. [link] shows the results of the survey.

x P ( x )
0 2 40
1 5 40
2
3 14 40
4 7 40
5 4 40

6 . Find the probability that a teenager is reminded two times.

  1. 8
  2. 8 40
  3. 6 40
  4. 2

7 . Find the expected number of times a teenager is reminded to do his or her chores.

  1. 15
  2. 2.78
  3. 1.0
  4. 3.13


Use the following information to answer the next two exercises: On any given day, approximately 37.5% of the cars parked in the De Anza parking garage are parked crookedly. We randomly survey 22 cars. We are interested in the number of cars that are parked crookedly.

8 . For every 22 cars, how many would you expect to be parked crookedly, on average?

  1. 8.25
  2. 11
  3. 18
  4. 7.5

9 . What is the probability that at least ten of the 22 cars are parked crookedly.

  1. 0.1263
  2. 0.1607
  3. 0.2870
  4. 0.8393

10 . Using a sample of 15 Stanford-Binet IQ scores, we wish to conduct a hypothesis test. Our claim is that the mean IQ score on the Stanford-Binet IQ test is more than 100. It is known that the standard deviation of all Stanford-Binet IQ scores is 15 points. The correct distribution to use for the hypothesis test is:

  1. Binomial
  2. Student's t
  3. Normal
  4. Uniform

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
Gokuna
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.
Muhammad
statistics is percentage only
Moha Reply
the first word is chance for that we use percentages
muhammad
it is not at all that statistics is a percentage only
Shambhavi
I need more examples
Luwam Reply
how to calculate sample needed
Jim Reply
mole of sample/mole ratio or Va Vb
Gokuna
how to I solve for arithmetic mean
Joe Reply
Yeah. for you to say.
James
yes
niharu
how do I solve for arithmetic mean
Joe Reply
please answer these questions
niharu
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.
Jim
*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
David
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.
Da
can you solve this problem
Gayanne Reply
yes
Harry
which problem
Larwubah
what is the meaning of correlation ratio?
Nayeem
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
peter
yo
Kailesh
what is the frequency
okoh Reply
Frequency is the number of all object which is comes from population or sample size
Faiqa
Denoted by f
Faiqa
number of all objects?
Amir
frequency is the rate of occurrence of an object
Leek
Explain nominal and ordinal variables
Oyinlola
 nominal variables are those variable which is used to “name,” a series of values.
Amir
while  ordinal scales provide good information about the order of choices,for example in a customer satisfaction survey.
Amir
what is the difference between Mean and Varience?
Amir
Sum of total object, divided by number of object is called mean
Faiqa
variance?
Amir
faiqa U didn't clear me.Sorry
Amir
what is df in statistics
Oyinlola
degre of freedom
Amir

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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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