A personnel director in a particular state claims that the mean annual income is the same in one of the state's counties (County A) as it is in another county (County B). In County A, a random sample of 18 residents has a mean annual income of $41,300 and a standard deviation of $8700. In County B, a random sample of 8 residents has a mean annual income of $38,600 and a standard deviation of $5600. At a = 0.10, answer parts (a) through (e). Assume the population variances are not equal. Assume the samples are random and independent, and the populations are normally distributed. (a) Identify the claim and state H, and Ha. Which is the correct claim below? O A. "The mean annual income in County A is greater than in County B." B. "The mean annual income in County A is less than County B." c. "The mean annual incomes in Counties A and B are equal." O D. "The mean annual incomes in Counties A and B are not equal." What are H, and H,? The null hypothesis, Ho, is µ1 = H2. The alternative hypothesis, Ha, is µ1 # H2. Which hypothesis is the claim? * The null hypothesis, Ho X The alternative hypothesis, Ha (b) Find the critical value(s) and identify the rejection region(s). Enter the critical value(s) below.

For a study conducted by the research department of a pharmaceutical company, 235 randomly selected individuals were asked to report the amount of money they spend annually on prescription allergy relief medication. The sample mean was found to be $17.80 with a standard deviation of $4.30 . A random sample of 250 individuals was selected independently of the first sample. These individuals reported their annual spending on non-prescription allergy relief medication. The mean of the second sample was found to be $18.20 with a standard deviation of $4.00 . As the sample sizes were quite large, it was assumed that the respective population standard deviations of the spending for prescription and non-prescription allergy relief medication could be estimated as the respective sample standard deviation values given above. Construct a 90% confidence interval for the difference −μ1μ2 between the mean spending on prescription allergy relief medication ( μ1 ) and the mean…

A company has rolled out a new process for sales people to use.  They were able to go back into the company records and pull all sales data from before the roll out.  Each sales person when they closed a sale had an average contract of $108 with a standard deviation of $12.  During the first month after the roll out, a sample of sales showed the average contract was $116.  Which statistical test could be used to see if this was a significant increase in contract size?

Statewide, the population as a whole watches 6.2 hours of TV per day. A random sample of 1017 senior citizens in the state reports watching an average of 5.9 hours per day, with a standard deviation of 0.7. is the difference significant