PLEASE HELP!

1.

(08.02 MC) A random sample of 200 employees at a specific company is asked to state their gender and annual salary. The results are recorded in the table.

Gender	$50,000	$75,000	$100,000	>$100,000
Male	29	34	12	20
Female	41	44	6	14

A chi-square test is used to test the null hypothesis that gender and salary are independent. Which statement is correct? (3 points)

	Fail to reject H0at the 0.10 significance level.
	Fail to reject H0at the 0.5 significance level.
	Reject H0at the 0.01 significance level.
	Reject H0at the 0.05 significance level.
	Reject H0at the 0.001 significance level.

2.

(07.02 HC) An experiment was conducted to compare plant growth by treating surrounding plant soil with one of two fertilizers. Fifty of 150 seedlings were randomly chosen to receive Fertilizer X. The rest received Fertilizer Y. The heights were recorded for each seedling, in centimeters, at the end of the study. The results obtained are shown. Fertilizer X: X₁= 12.4 cm, s₁= 4 cm Fertilizer Y: X₂= 18.7 cm, s₂= 3 cm We wish to determine whether there is a difference in height for the seedlings treated with the different fertilizers by testing the hypotheses H₀: _{2 1}= 0 and H_a: _{2 1} 0. Find the 90% confidence interval for _{2 1}and make a conclusion based on that confidence interval. (3 points)

	The 90% confidence interval is 6.3 7.37. The p-value is less than 0.10.
	The 90% confidence interval is 6.3 1.066. I would not reject the null hypothesis of no difference at the 0.10 level.
	The 90% confidence interval is 6.3 5.23. I would not reject the null hypothesis of no difference at the 0.10 level.
	The 90% confidence interval is 6.3 5.23. I would reject the null hypothesis of no difference at the 0.10 level.
	The 90% confidence interval is 6.3 1.066. I would reject the null hypothesis of no difference at the 0.10 level.

3.

(04.04 LC) The weight of apples at the grocery store follows a Normal distribution with a mean of = 5 ounces and a standard deviation of = 1 ounce. Suppose we pick nine apples at random from the basket and find their total weight, W. Which of the following statements describes the random variable W? (3 points)

	The random variable W is Normal, with a mean of five ounces and a standard deviation of one ounce.
	The random variable W is Normal, with a mean of 45 ounces and a standard deviation of three ounces.
	The random variable W is Normal, with a mean of five ounces and a standard deviation of three ounces.
	The random variable W is binomial, with a mean of 45 ounces and a standard deviation of nine ounces.
	The random variable W is binomial, with a mean of five ounces and a standard deviation of nine ounces.

4.

(04.04 LC) The number of purses a vendor sells daily has the probability distribution represented in the table.

Number of Purses, x	0	1	2	3	4	5
P(x)	0.35	0.15	0.2	0.2	0.03	0.07

If each purse sells for $50.00, what is the expected daily total dollar amount taken in by the vendor from the sale of purses? (3 points)

	$1.62
	$35.00
	$79.30
	$81.00
	$162.00

5.

(05.05 MC) Which of the following correctly describes how the width of a confidence interval for a population mean changes when the population standard deviation is known? (3 points)

	There is no change if just the sample size increases.
	The interval widens if the sample size decreases and confidence level stays the same.
	The interval narrows if the sample size decreases and confidence level stays the same.
	The interval widens if the sample size increases and the confidence level stays the same.
	The interval widens if the sample size stays the same and confidence level decreases.

6.

(06.02 LC) In conducting a test on the hypotheses H₀: = 250 and H_a:

	No error
	Type II error
	Type I error
	Standard deviation of the mean
	There is not enough information given

7.

(02.04 MC) Eighteen pairs of measurements were taken at random to estimate the relation between variables X and Y. A least-squares line was fitted to the collected data. The resulting residual plot is shown. (3 points)

\f10 8 6 6 5 Number of Chickens 4 2 0 0-3 4-6 7-9 10-12 13-15 16-18 19-21 22-24 25-27 28-30 31-33 34-36 37-39 40-42 43-45 Time, seconds\f1,000 500 Residuals 0 50 100 150 200 250 -500 -1,000 X