Multiple choice questions:
Question 1
To determine the sample size needed to estimate a population parameter, one must know the maximum error of the estimate.
True
False
Question 2
A simple random sample of 100 observations was taken from a large population and the sample mean and the standard deviation were determined to be 80 and 12 respectively. The standard error of the mean is 0.12
True
False
Question 3
In point estimation, data from the sample is used to estimate the population parameter
True
False
Question 4
The 95 percent confidence interval states that 95 percent of the sample means of a specified sample size selected from a population will lie within plus and minus 2.58 standard deviations of the hypothesized population mean.
True
False
Question 5
If a hypothesis is rejected at 95% confidence, it will always be rejected at 90% confidence.
True
False
Question 6
In hypothesis testing, the hypothesis tentatively assumed to be true is the alternative hypothesis.
True
False
Question 7
True
False
Question 8
No error is committed when the null hypothesis is rejected when it is true.
True
False
Question 9
Test for variances are always two-tailed
True
False
Question 10
To test the equality of two proportions one would use a z test.
True
False
Question 11
When the t test is used for testing the equality of two means, the populations must be normal.
True
False
Question 12
If the same diet is given to two groups of randomly selected individuals, the samples are considered to be independent.
True
False
Question 13
Regression analysis is a statistical procedure for developing a mathematical equation that describes how one dependent and one or more independent variables are related.
True
False
Question 14
If the correlation coefficient in a linear regression model is 2 or more, a very strong positive relation exists between the two variables.
True
False
Question 15
True
False
Question 16
The equation that describes how the dependent variable (y) is related to the independent variable (x) is called the regression equation.
True
False
Question 17
The test values for the chi squared goodness of fit test and the independence test are computed using the same formula.
True
False
Question 18
True
False
Question 19
True
False
Question 20
When three or more means are compared, one used analysis of variances technique.
True
False
Question 21
A member of Congress wants to determine her popularity in a certain part of the state. She indicates that the proportion of voters who will vote for her must be estimated within plus or minus 2 percent of the population proportion. Further, the 0.95 degree of confidence is to be used. In past elections, the representative received 40 percent of the popular vote in that area of the state. She doubts whether it has changed much. How many registered voters should be sampled?
A. 864
B. 5200
C. 2305
D. 2000
Question 22
Of 900 consumers surveyed, 414 said they were very enthusiastic about a new home decor scheme. What is the 99% confidence interval for the population proportion?
A. 30 and 40
B. 30 and 60
C. 31 and 51
D. 42 and 50
Question 23
For a given confidence interval, what is the interpretation of a 96% confidence level?
A. 96% chance that the given interval includes the true value of the population parameter
B. Approximately 96 out of 100 such intervals would include the true value of the population parameter
C. 4% chance that the given interval does not include the true value of the population parameter
D. Both "a" and "c" are true
Question 24
A. 1, 2, 3.
B. 2, 1, 3.
C. 3, 2, 1.
D. 3, 1, 2.
Question 25
A. smallest, reject H0.
B. largest, reject H0
C. smallest, reject H1
D. largest, reject H1.
Question 26
Which of the following examples illustrates a study that compares two population proportions?
A. The amount of saliva secreted daily by men and women.
B. The volume of air breathed daily by track runners and swimmers.
C. The percentage of men and women who are color blind.
D. The pounds of food digested daily by adult crocodiles and water buffaloes.
Question 27
B
C
D
Question 28
Suppose the least squares regression equation is Y' = 1202 + 1,133X. When X = 3, what does Y' equal?
A. 5,734
B. 8,000
C. 4,601
D. 4,050
Question 29
A -0.947 correlation coefficient has been found between two variables after examining 43 pairs of observations. What can be concluded?
A. There is a strong positive relationship between the two variables.
B. There is a strong negative relationship between the two variables.
C. There is a weak positive relationship between the two variables.
D. There is a weak negative relationship between the two variables.
Question 30
In a simple regression analysis (where Y is a dependent and X an independent variable), if the Y intercept is positive, then
A. there is a positive correlation between X and Y
B. if X is increased, Y must also increase
C. if Y is increased, X must also increase
D. a, b, and c are correct
E. None of the above alternatives are correct
Question 31
The null hypothesis in the ANOVA is that all the means are ______.
A. Variable
B. Equal
C. Unequal
D. Independent
Question 32
The degrees of freedom in a 4×3 contingency table are ______.
A. 12
B. 11
C. 6
D. 7
Question 33
A health club has six tennis courts. The owner hypothesizes that his patrons have no preference for a particular court. He observes how many people play on each court on a particular day. Compute the expected value for the data shown below.
A. 4.37
B. 10.3
C. 9.5
D. 5.72
Question 34
Many elementary school students in a school district currently have ear infections. A random sample of children in two different schools found that 16 of 42 at one school and 21 of 36 at the other had this infection. At the .05 level of significance, is there sufficient evidence to conclude that a difference exists between the proportion of students who have ear infections at one school and the other?
A. No, there is not sufficient information to reject the hypothesis that the proportions of students at the two schools who have ear infections are the same because the test value -1.78 is inside the acceptance region (-1.96,1.96).
B. Yes, there is sufficient information to reject the hypothesis that the proportions of students at the two schools who have ear infections are the same because the test value -2.34 is outside the acceptance region (-1.96,1.96).
C. Yes, there is sufficient information to reject the hypothesis that the proportions of students at the two schools who have ear infections are the same because the test value -8.76 is outside the acceptance region (-1.96,1.96).
D. Yes, there is sufficient information to reject the hypothesis that the proportions of students at the two schools who have ear infections are the same because the test value -15.73 is outside the acceptance region (-1.96,1.96).
Question 35
A dietician investigated whether apples washed in hot water or in cold water turned brown at different rates when exposed to air. She took 13 random apples and cut each in half. She washed one half of each apple in hot water and the other half in cold water, and then put both halves out in a tray. Her results (in hours until turning a particular shade of brown) are in the table below. At = .01, did she see a difference between the two treatments?
A. Yes, because the test value -3.16 is outside the range (-3.055, 3.055).
B. No, because the test value -1.09 is inside the range (-3.055, 3.055).
C. Yes, because the test value -1.09 is inside the range (-3.01, 3.01).
D. No, because the test value -3.16 is outside the range (-3.01, 3.01).