This module is a practice final for an associated elementary statistics textbook, Collaborative Statistics.
Questions 1-2 refer to the following:
An experiment consists of tossing two 12-sided dice (the numbers 1-12 are printed on the sides of each dice).
Let Event A = both dice show an even number
Let Event B = both dice show a number more than 8
Events A and B are:
| A. Mutually exclusive. |
| B. Independent. |
| C. Mutually exclusive and independent. |
| D. Neither mutually exclusive nor independent. |
Find P ( A | B )
A.  |
B.  |
C.  |
D.  |
Which of the following are TRUE when we perform a hypothesis test on matched or paired samples?
| A. Sample sizes are almost never small. |
| B. Two measurements are drawn from the same pair of individuals or objects. |
| C. Two sample means are compared to each other. |
| D. Answer choices B and C are both true. |
Questions 4 - 5 refer to the following:
118 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 |
Find the probability that a randomly chosen student is male or has a bedroom painted with light colors.
A.  |
B.  |
C.  |
D.  |
Find the probability that a randomly chosen student is male given the student’s bedroom is painted with dark colors.
A.  |
B.  |
C.  |
D.  |
Questions 6 – 7 refer to the following:
We are interested in the number of times a teenager must be reminded to do his/her chores each week. A survey of 40 mothers was conducted. The table below shows the results of the survey.
| x | P ( x ) |
| 0 |  |
| 1 |  |
| 2 | |
| 3 |  |
| 4 |  |
| 5 |  |
Find the probability that a teenager is reminded 2 times.
| A. 8 |
B.  |
C.  |
| D. 2 |
Find the expected number of times a teenager is reminded to do his/her chores.
| A. 15 |
| B. 2.78 |
| C. 1.0 |
| D. 3.13 |
Questions 8 – 9 refer to the following:
On any given day, approximately 37.5% of the cars parked in the De Anza parking structure are parked crookedly. (Survey done by Kathy Plum.) We randomly survey 22 cars. We are interested in the number of cars that are parked crookedly.
For every 22 cars, how many would you expect to be parked crookedly, on average?
| A. 8.25 |
| B. 11 |
| C. 18 |
| D. 7.5 |
What is the probability that at least 10 of the 22 cars are parked crookedly.
| A. 0.1263 |
| B. 0.1607 |
| C. 0.2870 |
| D. 0.8393 |
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:
| A. Binomial |
| B. Student's-t |
| C. Normal |
| D. Uniform |
Questions 11 – 13 refer to the following:
De Anza College keeps statistics on the pass rate of students who enroll in math classes. In a sample of 1795 students enrolled in Math 1A (1st quarter calculus), 1428 passed the course. In a sample of 856 students enrolled in Math 1B (2nd quarter calculus), 662 passed. In general, are the pass rates of Math 1A and Math 1B statistically the same? Let A = the subscript for Math 1A and B = the subscript for Math 1B.
If you were to conduct an appropriate hypothesis test, the alternate hypothesis would be:
| A. Ha: pA = pB |
| B. Ha: pA > pB |
| C. Ho: pA = pB |
| D. Ha: pA ≠ pB |
The Type I error is to:
| A. conclude that the pass rate for Math 1A is the same as the pass rate for Math 1B when, in fact, the pass rates are different. |
| B. conclude that the pass rate for Math 1A is different than the pass rate for Math 1B when, in fact, the pass rates are the same. |
| C. conclude that the pass rate for Math 1A is greater than the pass rate for Math 1B when, in fact, the pass rate for Math 1A is less than the pass rate for Math 1B. |
| D. conclude that the pass rate for Math 1A is the same as the pass rate for Math 1B when, in fact, they are the same. |
The correct decision is to:
| A. reject Ho |
| B. not reject Ho |
| C. There is not enough information given to conduct the hypothesis test |
Kia, Alejandra, and Iris are runners on the track teams at three different schools. Their running times, in minutes, and the statistics for the track teams at their respective schools, for a one mile run, are given in the table below:
| Running Time | School Average Running Time | School Standard Deviation | |
|---|---|---|---|
| Kia | 4.9 | 5.2 | .15 |
| Alejandra | 4.2 | 4.6 | .25 |
| Iris | 4.5 | 4.9 | .12 |
Which student is the BEST when compared to the other runners at her school?
| A. Kia |
| B. Alejandra |
| C. Iris |
| D. Impossible to determine |
Questions 15 – 16 refer to the following:
The following adult ski sweater prices are from the Gorsuch Ltd. Winter catalog:
{ $212 ,$292 ,$278 ,$199 $280 , $236 }
Assume the underlying sweater price population is approximately normal. The null hypothesis is that the mean price of adult ski sweaters from Gorsuch Ltd. is at least $275.
The correct distribution to use for the hypothesis test is:
| A. Normal |
| B. Binomial |
| C. Student's-t |
| D. Exponential |
