Question

In a study of academic procrastination, it was determined that for a random sample of 18 undergrad students at a mid-size public university, the mean time spent studying for the final exam in an intro statistics course was 7.74 hours with a standard deviation of 3.40 hours. What is the point estimate of the mean final exam study time for all undergrad students?

In a study of academic procrastination, it was determined that for a random sample of 18 undergrad students at a mid-size public university, the mean time spent studying for the final exam in an intro statistics course was 7.74 hours with a standard deviation of 3.40 hours. To a 90% confidence interval for the mean time spent studying for the intro statistics final exam for all undergrad students, the critical value needed would be ________.

In a study of academic procrastination, it was determined that for a random sample of 18 undergrad students at a mid-size public university, the mean time spent studying for the final exam in an intro statistics course was 7.74 hours with a standard deviation of 3.40 hours. Construct a 90% confidence interval for the mean time spent studying for the intro statistics final exam.

A random sample of 526 U.S. businesses found that 137 of the 526 businesses had fired workers for misuse of the Internet. The point estimate of the proportion of U.S. businesses who have fired workers for misuse of the Internet is __________.

A random sample of 526 U.S. businesses found that 137 of the 526 businesses had fired workers for misuse of the Internet. Compute a 98% confidence interval for the proportion of all U.S. businesses who have fired workers for misuse of the Internet. The margin of error for this confidence interval would be ________.

A simple random sample of n = 250 is drawn from a population with a standard deviation of 312. From the sample we determine the mean is 1500. In order to compute a confidence interval for the population mean we would use which of the following to compute the margin of error?

A new type of fertilizer is being tested on a plot of land in an orange grove, to see whether it increases the amount of fruit produced. The mean number of pounds of fruit on this plot of land with the old fertilizer was 400 pounds.Agriculture scientists believe that the new fertilizer may increase the yield. State the appropriate null and alternative hypotheses.

According to FICO the mean credit score is 703.5. A credit analyst wondered whether high income individuals (income over $100K per year) had higher credit scores. The analyst obtained a random sample of 40 high-income individuals and determined the mean credit score to be 714.2 with a standard deviation of 53.2. Calculate the test-statistic for a test of H0: μ ≤ 703.5 versus H1: μ > 703.5. The test statistic value (rounded to 2 decimal places) is ________.

According to the Centers for Disease Control (CDC), 15.2% of American adults experience migraine headaches. Stress is a major contributor to the frequency and intensity of headaches. A massage therapist feels that she has a technique that can reduce the frequency and intensity of migraines. A random sample of 500 American adults participate in the massage therapist’s program and 65 report experiencing migraines. Does this sample provide evidence that the proportion of American adults who experience migraines is reduced by the massage therapist’s program? Calculate the test-statistic for a test of Ho: p ≥ 0.152 versus H1: p < 0.152. The test statistic (rounded to 2 decimal places) is ______.

Answer 1