Question

Suppose you are a researcher in a hospital. You are experimenting with a new tranquilizer. You collect data from a random sample of 9 patients. The period of effectiveness of the tranquilizer for each patient (in hours) is as follows:

2.5

2

2.3

2.3

2.5

2.1

2.8

2.6

2.8

What is a point estimate for the population mean length of time. (Round answer to 4 decimal places)

Which distribution should you use for this problem?

• normal distribution
• t-distribution

What must be true in order to construct a confidence interval in this situation? (1 point)

• The sample size must be greater than 30
• The population mean must be known
• The population must be approximately normal and/or the sample size must be at greater than 30
• The population standard deviation must be known

The margin of error is 0.27308077337717.
Construct a 98% confidence interval for the population mean length of time. Enter your answer as an open-interval (i.e., parentheses) Round upper and lower bounds to two decimal places

What does it mean to be "98% confident" in this problem?

• 98% of all simple random samples of size 9 from this population will result in confidence intervals that contain the population mean
• There is a 98% chance that the confidence interval contains the population mean
• The confidence interval contains 98% of all samples

Suppose that the company releases a statement that the mean time for all patients is 2 hours.

Is this possible?

• Yes
• No

Is it likely?

• No
• Yes

Answer 1