1.)For air travelers, one of the biggest complaints is of the waiting time between when the airplane taxis away from the terminal until the flight takes off. This waiting time is known to have a skewed-right distribution with a mean of 10 minutes and a standard deviation of 8 minutes. Suppose 100 flights have been randomly sampled. Describe the sampling distribution of the mean waiting time between when the airplane taxis away from the terminal until the flight takes off for these 100 flights. Answer
Distribution is skewed-right with mean = 10 minutes and standard error = 0.8 minutes.
Distribution is skewed-right with mean = 10 minutes and standard error = 8 minutes.
Distribution is approximately normal with mean = 10 minutes and standard error = 0.8 minutes.
Distribution is approximately normal with mean = 10 minutes and standard error = 8 minutes.

2.)
At a computer manufacturing company, the actual size of computer chips is normally distributed with a mean of 1 centimeter and a standard deviation of 0.1 centimeter. A random sample of 12 computer chips is taken. What is the standard error for the sample mean?Answer
0.029
0.050
0.091
0.120

3.)
A catalog company that receives the majority of its orders by telephone conducted a study to determine how long customers were willing to wait on hold before ordering a product. The length of time was found to be a random variable best approximated by an exponential distribution with a mean equal to 3 minutes. What proportion of customers having to hold more than 4.5 minutes will hang up before placing an order?Answer
0.22313
0.48658
0.51342
0.77687

4.)
Which of the following statements is true?Answer
If the confidence interval estimate for the regression slope coefficient crosses over zero, the average change in y for a one-unit change in x may be zero.
If the regression slope coefficient is very close to zero, this means that the relationship between the x and y variable is statistically insignificant.
A statistically significant regression slope coefficient indicates that for a one-unit change in y there will be a positive change in x by an amount equal to the regression slope coefficient.
It is acceptable to make predictions for y using x values that are outside the range of the data that was used in the regression.

5.)
An economist is interested in studying the incomes of consumers in a particular region. The population standard deviation is known to be $1,000. A random sample of 50 individuals resulted in an average income of $15,000. What total sample size would the economist need to use for a 95% confidence interval if the width of the interval should not be more than $100?Answer
n = 1537
n = 385
n = 40
n = 20