A survey of 100 businesses revealed that the mean after-tax profit was $80,000. Assume the population standard deviation is $15,000. Using a 95% confidence level, calculate the confidence interval of the mean after tax profit. Lower Class Limit = Round the final answer to the nearest dollar. Upper Class Limit = Round the final answer to the nearest dollar.

Hypothesis test For a certain nationwide standardized test there are two commonly used preparation products on the market: StudyFocus and Prepara. A researcher in the Education department at a nearby university wants to determine if there is any difference between the two products on the mean score on the test by their users. The researcher obtains the scores on the test from a random sample of 16 users of StudyFocus and a random sample of 14 users of Prepara. (These samples are chosen independently.) These data are shown in the table. ? StudyFocus Prepara Send data to calculator 408, 400, 460, 587, 485, 559, 470, 439, 453, 531, 491, 481, 529, 494, 581, 397 510, 553, 504, 525, 549, 500, 525, 561, 510, 493, 498, 512, 517, 546 V Scores Send data to Excel Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places. (If necessary, consult a list of formulas.) Explanation Assume that the two populations of scores are…

Subgroup of Participants Supine SBP Mean (SD) Standing SBP Mean (SD) Percent with > 5.0 Decrease Percent with > 5.0 Increase White women (N = 301) 120.4 (18.4) 120.0 (18.8) 32.6% 32.2% African-American women (N = 107) 122.7 (19.3) 122.8 (19.4) 30.2% 31.9% White men (N = 339) 121.2 (18.9) 120.2 (19.9) 39.5% 25.6% African-American men (N = 95) 124.7 (20.4) 125.9 (21.6) 13.7% 51.3% Total (N = 842) 121.5 (19.0) 121.1 (19.5) 29.8% 31.7% Would it be possible to analyze data in table 2 with a chi-square test? if yes, specify how