11. If the odds of a horse winning a race are 2 to 1, then the probability of this horse winning the race is .
a. 1/4
b. 1/3
c. 1/2
d. 2/3
e. 2/10
12. There are, generally speaking, two types of statistical inference. They are:
a. sample estimation and population estimation
b. confidence interval estimation and hypothesis testing
c. interval estimation for a mean and interval estimation for a proportion
d. independent sample estimation and dependent sample estimation
e. none of the above
13. The t distribution has degrees of freedom.
a. n
b. 2
c. 10
d. n 1
e. trillion
14. If you are constructing a confidence interval for a single mean, the confidence interval will with an increase in the sample size.
a. decreases
b. increases
c. stays the same
d. may increase or decrease, depending on the sample data
15. As the sample size increases, the t distribution becomes more similar to the __ distribution.
a. normal
b. exponential
c. F
d. chi-square
e. binomial
16. A parameter, such as .png”>, is sometimes referred to as a ________ parameter, because many times we need its value even though it is not the parameter of primary interest.
a. special
b. random
c. nuisance
d. independent
e. dependent
17. When you calculate the sample size for a proportion, you use an estimate for the population proportion (.png”>). A conservative value for n can be obtained by using .png”>= .
a. 0.0
b. 0.05
c. 0.10
d. 0.50
e. 1.00
QUESTIONS 18 THROUGH 23 ARE BASED ON THE FOLLOWING INFORMATION:
The following values have been calculated using the TDIST and TINV functions in Excel. These values come from a t distribution with 15 degrees of freedom.
These values represent the probability to the right of the given positive values.
Value
t probability
1.00
0.1636
1.20
0.1209
1.40
0.0872
These values represent the t value for a given probability.
Probability
t value
0.20
1.3178
0.10
1.7109
0.05
2.0639
18. What is the probability of a t-value smaller 1.00?
a. 0.1209
b. 0.1636
c. 0.8364
d. 0.8791
19. What is the probability of a t-value larger than 1.20?
a. 0.0872
b. 0.1209
c. 0.1636
d. 0.2000
20. What is the probability of a t-value between 1.40 and +1.40?
a. 0.7582
b. 0.8256
c. 0.9128
d. 0.9500