1. Dullco Manufacturing claims that its alkaline batteries last at least 40 hours on average in a certain type of portable CD player. But tests on a random sample of 20 batteries from a day's large production run showed a mean battery life of 37.8 hours with a standard deviation of 5.4 hours. To test DullCo's hypothesis, the test statistic is:

Group of answer choices

1.82

-1.980

-1.82

-2.101

-1.728

-1.960

2. Ersatz Beneficial Insurance wants to estimate the cost of damage to cars due to accidents. The standard deviation of the cost is known to be $200. They want to estimate the mean cost using a 95 percent confidence interval within $20. What is the minimum sample size n?

Group of answer choices

1083

425

4002

385

1537

865

3. Using the conventional polling definition, find the approximate margin of error for a customer satisfaction survey of 450 customers who have recently dined at Applebee's. (Please use hand calculation for approx answer)

Group of answer choices

6.5 percent

4.6 percent

5.5 percent

4.2 percent

7.1 percent

5.0 percent

4. The time required for a citizen to complete the 2020 U.S. Census "long" form is normally distributed with a mean of 40 minutes and a standard deviation of 12 minutes. What is the third quartile (in minutes) for the time required to complete the form?

Group of answer choices

48.09

46.75

50

52.50

47.00

44.75