Statistics Exam
1. For a population with a mean of 25 and a variance of 0, what can we conclude?: *
There is only one element in the population.
There are no elements in the population.
All the elements in the population are 25.
None of the above.
2. What is the standard deviation of the following data set?
{8, 9, 9, 9, 10, 11, 11, 12}: *
1.27
2.54
1.13
3.66
3. Which of the following pairs of events are mutually exclusive?: *
Odd numbers; Number 5
Even numbers; Numbers greater than 10
Numbers less than 5; All negative numbers
A: Numbers above 100; Numbers less than -200
4. There are two urns marked A and B. Urn A contains 2 red marbles and 1 blue marble. Urn B contains 1 red
blue marbles. A coin is to be tossed. If it lands on heads, a marble is drawn from Urn A. If it lands on tails a m
is drawn from Urn B. What is the probability of tossing a heads and drawing a red marble?: *
1/2
1/3
1/6
1/12
5. A summer camp complex houses 200 campers. 120 campers are male, 50 campers are senior campers, and
senior male campers. A camper is selected at random. What is the probability of selecting a non-senior camp
given the camper is female?: *
7/20
7/15
7/8
2/5
6. Suppose a die is weighted, and each number has the following probability of being rolled. If the die is thro
the top face is an odd number, what is the probability that the die shows a four?: *
0.5
0.1
0
0.05
7. A standard normal distribution has which of the following properties?: *
The mean is equal to the variance.
The mean equal to 1 and variance equal to 1.
The mean equal to 0 and standard deviation equal to 0.
The mean equal to 0 and variance equal to 1.
8. A sample is normally distributed with a mean of 4200 and a standard deviation of 300. What proportion of
samples would have 4800 cells or more?: *
0.0228
-1.67
0.4772
2.00
9. If a normal distribution has mean of 200 and standard deviation of 20, find M such that...: *
204
239
250
259
10. If Z is a standard normal variable, what is the area to the left of Z = 0.65?: *
0.7422
0.6500
0.3500
0.2242
11. The distribution of lifetimes for light bulb Type A is normally distributed with a mean of 1000 hours and
standard deviation of 100 hours. What is the 33rd percentile of the distribution of lifetimes of light bulb Type
125
330
560
956
12. Assume that the exam scores of 600 students are normally distributed with a mean of 76 and a standard
deviation of 8. What is the number of students scoring between 70 and 82?: *
328
272
260
164
13. : *
0.2167
0.3921
0.5997
0.6915
14. A high school coach thinks ballet training will improve the batting performance of his baseball team. He
randomly selects half of the team to take ballet training before the baseball season begins, while the other hal
not take any training. He will then compare the season batting the groups. What is the independent variable?:
batting average
ballet training
team size
grades of the players in ballet school
15. A large company is considering opening a franchise in St. Louis and wants to estimate the mean househo
income for the area using a simple random sample of households. Based on information from a pilot study, th
company assumes that the standard deviation of household incomes is $7,200. Of the following, which is the
number of households that should be surveyed to obtain an estimate that is within $200 of the true mean hous
income with 95 percent confidence?: *
1,375
1,300
5,200
5,500
7,700
16. Which of the following occurrences always result in a Type I error?: *
The null hypothesis is rejected when it is, in fact, true.
The null hypothesis is not rejected when it is, in fact, false.
The research hypothesis is rejected when it is, in fact, true.
The research hypothesis is not rejected when it is, in fact, false.
17. If the sample means for each of the treatment groups were identical, what would the observed value of the
ANOVA F-ratio be?: *
1.0
0.0
0.0 - 1.0
<0
18. If X has an F distribution with df=4,5, what is the value of c where P (X < c) = .95?: *
6.39
6.26
5.19
5.05
19. If the correlation coefficient is 0.61, what is the proportion of the variation in the dependent variable expl
by the variation in the independent variable?: *
37%
61%
98%
None of the above
20. If the correlation between scores on a stress test and scores on an anxiety test is high and positive, what ca
conclude?: *
Anxiety causes stress.
Those who score low on one test tend to score high on the other.
Those who score low on one test tend to score low on the other.
No prediction can be made.
21. Four people are in line to play baseball, and the team captain can choose any three people to fill spots on
team. How many different groups of three people could he choose?: *
a.
b.
c.
d.
22. Which expression is used to find the mean of a binomially distributed variable?: *
a.
b.
c.
d.
23. What is the total number of possible 3-letter code words, in which all three letters are different?: *
520
456,976
17,576
15,600
24. A student has a box of 30 candies. 8 candies are blue, 10 candies are green, and 12 candies are red. Given
the first candy eaten is green, what is the probability that the next candy selected at random is also green?: *
8/29
8/9
9/29
90/600
25. Three dice are tossed, and the total number of dots on the sides facing up is counted. What is the sample s
*
S = {3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18}
S = {2, 4, 6, 8, 10, 12, 14, 16, 18}
S = {1, 2, 3, 4, 5, 6}
S = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18}
Submit