1.The majority of clothing retailers use mannequins to display their merchandise, with approximately onethird displaying mannequins with heads and twothirds displaying mannequins without heads. Researchers recruited126female participants and assigned each to one of the two mannequin styles (head/headless). Participants were asked to imagine that they wanted to buy a new dress and told to go to a named store to make their purchase. They then viewed the dress displayed on a mannequin (head or headless) and were asked whether or not they would buy the dress.

Of the63participants viewing the dress displayed on a mannequin with a head,18indicated that they would buy the dress, while only10of the63participants viewing the headless mannequin indicated that they would buy the dress.

Assuming the conditions are met, calculate the test statistic and-value.Give the test statistic to two decimal places and-valueto four decimal places.

||= 1.76

-value=

2.STATE: Lyme disease is spread in the northeastern United States by infected ticks. The ticks are infected mainly by feeding on mice, so more mice result in more infected ticks. The mouse population rises and falls with the abundance of acorns, their favored food. Experimenters studied two similar forest areas in a year when the acorn crop failed. They added hundreds of thousands of acorns to one area to imitate an abundant acorn crop while leaving the other area untouched. The next spring,54of the72mice trapped in the first area were in breeding condition, versus10of the17mice trapped in the second area. Estimate the difference between the proportions of mice ready to breed in good acorn years and bad acorn years. (Use90%confidence. Be sure to justify your choice of the confidence interval.)

SOLVE: Use the plus-four method to find 1, 2, and the upper and lower bound of the90%confidence interval. Give your answers to four decimal places.

1=

2=

lower bound:

upper bound: