# Liberty BUSI 230 Exam 3 Answers Complete Solutions

You would just need to put your values into excel. I put all mathematical formulas. They are the same questions with different values.

In general, a large value for a t statistic (far from zero) is an indication that the sample data are not consistent with the null hypothesis.

If all other factors are held constant, increasing the sample size will do the following.

A Type I error is defined as the following.

The t distribution is symmetrical and has a mean of zero.

## STATUS

Rejecting the null hypothesis means that the sample outcome is very unlikely to have occurred if H0 is true.

If a specific sample leads to rejecting the null hypothesis with α = .05, then the same sample would certainly lead to rejecting the null hypothesis if α were changed to .01.

A Type II error is defined as the following.

There is always a possibility that the decision reached in a hypothesis test is incorrect.

In most research situations, the goal of a hypothesis test is to reject the null hypothesis.

Let x represent the dollar amount spent on supermarket impulse buying in a 10-minute (unplanned) shopping interval. Based on a certain article, the mean of the x distribution is about $47 and the estimated standard deviation is about $9.

(a) Consider a random sample of n = 80 customers, each of whom has 10 minutes of unplanned shopping time in a supermarket. From the central limit theorem, what can you say about the probability distribution of x, the average amount spent by these customers due to impulse buying? What are the mean and standard deviation of the x distribution?

Is it necessary to make any assumption about the x distribution? Explain your answer.

(b) What is the probability that x is between $45 and $49? (Round your answer to four decimal places.)

(c) Let us assume that x has a distribution that is approximately normal. What is the probability that x is between $45 and $49? (Round your answer to four decimal places.)

(d) In part (b), we used x, the average amount spent, computed for 80 customers. In part (c), we used x, the amount spent by only one customer. The answers to parts (b) and (c) are very different. Why would this happen?