7.2 A single population mean using the student t distribution --  (Page 4/21)

Identify the following:

1. $\overline{x}$ =_______
2. $s_x$ =_______
3. n =_______
4. n – 1 =_______

Define the random variables X and $\overline{X}$ in words.

Which distribution should you use for this problem?

Construct a 95% confidence interval for the population mean time spent waiting. State the confidence interval, sketch the graph, and calculate the error bound.

Explain in complete sentences what the confidence interval means.

Identify the following:

1. $\overline{x}$ =_______
2. $s_x$ =_______
3. n =_______
4. n – 1 =_______

Define the random variable X in words.

Define the random variable $\overline{X}$ in words.

Which distribution should you use for this problem?

Construct a 99% confidence interval for the population mean hours spent watching television per month. (a) State the confidence interval, (b) sketch the graph, and (c) calculate the error bound.

Why would the error bound change if the confidence level were lowered to 95%?

Calculate the following:

1. $\overline{x}$ =______
2. $s_x$ =______
3. n =______

Define the random variable $\overline{X}$ in words.

What is $\overline{x}$ estimating?

Is ${\sigma }_x$ known?

As a result of your answer to [link] , state the exact distribution to use when calculating the confidence interval.

How much area is in both tails (combined)?

How much area is in each tail?

Calculate the following:

1. lower limit
2. upper limit
3. error bound

The 95% confidence interval is_____.

Fill in the blanks on the graph with the areas, the upper and lower limits of the Confidence Interval and the sample mean.

In one complete sentence, explain what the interval means.

Using the same $\overline{x}$ , $s_x$ , and level of confidence, suppose that n were 69 instead of 39. Would the error bound become larger or smaller? How do you know?

Using the same $\overline{x}$ , $s_x$ , and n = 39, how would the error bound change if the confidence level were reduced to 90%? Why?