Question 1

Assume that a sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level. Round the margin of error to four decimal places. 98% confidence; the sample size is 800, of which 40% are successes
A.
0.0339
B.
0.0446
C.
0.0403
D.
0.0355
1 points
Question 2

Find the value of that corresponds to a confidence level of 91%.
A.
1.75
B.
1.34
C.
1.645
D.
1.70
1 points
Question 3

Find the appropriate critical value for the following: 99% confidence level ; n = 17; σ is unknown; population appears to be normally distributed.
A.
zα/2 = 2.567
B.
zα/2 = 2.583
C.
tα/2 = 2.898
D.
tα/2 = 2.921
2 points
Question 4

Use the given degree of confidence and sample data to construct a confidence interval for the population proportion p. n = 195, x = 162; 95% confidence
A.
0.788 < p < 0.873
B.
0.777 < p < 0.884
C.
0.789 < p < 0.873
D.
0.778 < p < 0.883
1 points
Question 5

Thirty randomly selected students took the calculus final. If the sample mean was 95 and the standard deviation was 6.6, construct a 99% confidence interval for the mean score of all students.
A.
92.03 < μ < 97.97
B.
92.95 < μ < 97.05
C.
91.68 < μ < 98.32
D.
91.69 < μ < 98.31
1 points
Question 6

50 people are selected randomly from a certain population and it is found that 12 people in the sample are over 6 feet tall. What is the point estimate of the proportion of people in the population who are over 6 feet tall?
A.
0.18
B.
0.76
C.
0.24
D.
0.50
2 points
Question 7

Use the given data to find the minimum sample size required to estimate the population proportion. Margin of error: 0.028; confidence level: 99%; and unknown
A.
2223
B.
2115
C.
1116
D.
1939