The Ice Chalet offers dozens of different beginning iceskating classes. All of the class names are put into a 21,904; 2,266; 9,414; 7,681; 3,200; 17,500; 9,200; 7,380; 18,314; 6,557; 13,713; 17,768; 7,493; 2,771; girls and 14 boys. Suppose that we are interested in the true proportion of boys aces 8 to 12 in all beginning populating classes at the Ice Chalet. Assume that the children in the selected class are a and class are a random sample of the A report said that the average blood pressure is 121.91 for a sample of 35 white males aged 35-44 in Canada. he sample standard deviation of systolic blood pressure is 6.18. Find the blood pressure for white males aged 35-44 in Canada. We want to construct a 9 skating classes at the to confidence interval for the true proportion of boys in the ages 8 to 12 beginning ice- (a) Assume the underlying population is normal. classes at the Ice Chalet. Select the correct graph of the normal density curve, with properly labeled areas, upper and lower limits of the confidence interval, and the sample proportion. Number o (119.887, 124.133) 4 CL = 0.92 Number o (119.787, 124.033) n-1: o (119.863, 123.957) * = 0.04 (119.963, 124.057) 2 = 0.04 (b) Define the random variables X and X in words 6 0.175 0.2494 CL = 0.92 X is the number of students enrolled at a community college in the United States. X is the mean number of students enrolled from a sample of 20 community colleges in the United States. A is the mean number of students enrolled from a sample of 20 community colleges in the United States X is the number of students enrolled at a community college in the United States. * = 0.04 2 = 0.04 is the number of students enrolled from a sample of 20 community colleges in the United States. X is the mean number of students enrolled in a community college in the United States. 0.7653 0.825 0.8847 A is the number of students enrolled at a community college in the United States. X is the mean number CL = 0.9 of students enrolled from the population of community colleges in the United States. A is the number of students enrolled at a community college in the United States. X is the number of students enrolled from a sample of 20 community colleges in the United States. * = 0.04 g = 0.04 0.1153 0.175 0.2347 (c) Which distribution should you use for this problem? Explain your choice. CL = 0.92 O X ~ t19. since the sample size is small o is being used as an estimate for s. * = 0.08 * = 0.08 O X ~ t20, since the san stimate for s. A confidence interval for a mean is (-17, 15). This interval would be wider if 0.1006 0.175 0.2494 X ~ t19, since the sample size is eing used as an estimate for a. O X ~ t20 . since the sample size is small and s is being used as an estimate for a. . The sample mean was larger or the variability of the data was larger CL = 0.92 The variability of the data was small, or the san X ~ N (10,080, 7,337), since the underlying population is normal. The investigator wanted to be more confident of their results, or there was more information. The variability of the data was larger, or the investigator wanted to be more confident. = 0.04 2= 0.04 None of the above . 0.7506 0.825 0.8994 States . (d) Construct a 99% confidence interval for the population mean enrollme int at community colleges in the United Enter your answer in interval notation. 5 1 Round your answer to the nearest integer. Do not round any intermediate calculations. (e) What will happen to the error bound and confidence interval if 500 comm The error bound and confidence interval will both de variability in the sample. le size decreases The error bound and confidence interval will both de variability in the sample. o The error bound and confidence variability in the sample. ple size increases The error bound and confidence interval will both in variability in the sample . easing the sample size decreases The Academy of Orthopedic Surgeons states that 23% of women wear shoes that are too small for their feet. A researcher wants to be 98% confident that this proportion is within 0.015 of the true proportion. How large a sample is necessary? 0 5, 068 2 O 2,555 O 4,259 O 3, 407