A random sample of 400 statistics students finds that the average time spent on an exam is 50 minutes with a sample standard deviation of 5 minutes.

1.A random sample of 400 statistics students finds that the average time spent on an exam is 50 minutes with a sample standard deviation of 5 minutes. The standard error (SE) for the average time spent is:

A)0.5 minutes

B)0.25 minutes

C)0.0125 minutes

D)5.0 minutes

2.Everything else being equal, an increase in sample size from 100 to 400 will result in the standard error (SE) for the average _________.

A)decreasing to ¼ of what it was for the sample size of 100

B)decreasing to ½ of what it was for the sample size of 100

C)increasing to 2 times what it was for the sample size of 100

D)increasing to 4 times what it was for the sample size of 100

3.A random sample of 100 full time graduate students in the College of Science is taken to estimate the amount spent on textbooks this semester. The sampled students spent an average of $400 with a sample standard deviation of $100. A 95% confidence interval for the average amount spent by all full time graduate students in the College of Science would be: 

A)$400 +/- $100

B)$400 +/- $200

C)$400 +/- $10

D)$400 +/- $20

4.A random sample of 225 Penn State football season ticket holders is taken to estimate the population average amount spent in State College on a typical home football game weekend. The sample average was $500 with a sample standard deviation of $75. A 95% confidence interval for the average amount spent by all Penn State Football season ticket holders on a typical home football game weekend is: 

A)$500 +/- $75

B)$500 +/- $5

C)$500 +/- $10

D)$500 +/- $150

5.A random sample of 81 Statistics undergraduate students found that the average amount of hours of sleep per week during the past semester was 45.5 hours with a sample standard deviation of 3 hours. A 95% confidence interval for the average amount of hours of sleep per week by all Statistics undergraduate students is: 

A)45.5 +/- 0.666 hours

B)45.5 +/- 0.333 hours

C)45.5 +/- 3 hours

D)45.5 +/- 6 hours