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.
Please respond to the question 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
Please respond to the question above.
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
Please respond to the question above.
4. There are two urns marked A and B. Urn A contains 2 red marbles and 1 blue marble. Urn B contains 1 red and 2 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 marble 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
Please respond to the question above.
5. A summer camp complex houses 200 campers. 120 campers are male, 50 campers are senior campers, and 40 are senior male campers. A camper is selected at random. What is the probability of selecting a non-senior camper, given the camper is female?: *
7/20
7/15
7/8
2/5
Please respond to the question above.
6. Suppose a die is weighted, and each number has the following probability of being rolled. If the die is thrown and the top face is an odd number, what is the probability that the die shows a four?: *
0.5
0.1
0
0.05
Please respond to the question above.
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.
Please respond to the question above.
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
Please respond to the question above.
9. If a normal distribution has mean of 200 and standard deviation of 20, find M such that...: *
204
239
250
259
Please respond to the question above.
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
Please respond to the question above.
11. The distribution of lifetimes for light bulb Type A is normally distributed with a mean of 1000 hours and a standard deviation of 100 hours. What is the 33rd percentile of the distribution of lifetimes of light bulb Type A?: *
125
330
560
956
Please respond to the question above.
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
Please respond to the question above.
13. : *
0.2167
0.3921
0.5997
0.6915
Please respond to the question above.
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 half does 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
Please respond to the question above.
15. A large company is considering opening a franchise in St. Louis and wants to estimate the mean household income for the area using a simple random sample of households. Based on information from a pilot study, the company assumes that the standard deviation of household incomes is $7,200. Of the following, which is the least number of households that should be surveyed to obtain an estimate that is within $200 of the true mean household income with 95 percent confidence?: *
1,375
1,300
5,200
5,500
7,700
Please respond to the question above.
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.
Please respond to the question above.
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
Please respond to the question above.
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
Please respond to the question above.
19. If the correlation coefficient is 0.61, what is the proportion of the variation in the dependent variable explained by the variation in the independent variable?: *
37%
61%
98%
None of the above
Please respond to the question above.
20. If the correlation between scores on a stress test and scores on an anxiety test is high and positive, what can we 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.
Please respond to the question above.
21. Four people are in line to play baseball, and the team captain can choose any three people to fill spots on his team. How many different groups of three people could he choose?: *
a.
b.
c.
d.
Please respond to the question above.
22. Which expression is used to find the mean of a binomially distributed variable?: *
a.
b.
c.
d.
Please respond to the question above.
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
Please respond to the question above.
24. A student has a box of 30 candies. 8 candies are blue, 10 candies are green, and 12 candies are red. Given that 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
Please respond to the question above.
25. Three dice are tossed, and the total number of dots on the sides facing up is counted. What is the sample space?: *
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}
Please respond to the question above.
There are one or more errors in your responses above. Please check your responses before continuing.