Sum18-Math 1342-A2-CRN30347-ONLINE Paola Colmenero ? | 7/5/18 8:51 PM Test: Exam
ID: 2946407 • Letter: S
Question
Sum18-Math 1342-A2-CRN30347-ONLINE Paola Colmenero ? | 7/5/18 8:51 PM Test: Exam3-over Ch 6 &7 Post-Test(GRADED) Time Remaining: 06:49:27 7 Subna Test This Question: 1 pt 15 of 20 (17 complete) This Test: 20 pts possible Question Help A simple random sample from a population with a normal distribution of 104 body temperatures has x = 98.50 F and s-0 67 F. Construct an 80% confidence interval estimate of the standard deviation of body temperature of all healthy humans. Is it safe to conclude that the population standard deviation is less than 2.20°F? Click the icon to view the table of Chi-Square critical values. Round to two decimal places as needed.) Is it safe to conclude that the population standard deviation is less than 2.20°F? A. This conclusion is safe because 2.20°F is outside the confidence interval O B. This conclusion is not safe because 2.20°F is in the confidence interval. ° C. This conclusion is safe because 2.20°F is in the confidence interval. O D. This conclusion is not safe because 2.20°F is outside the confidence interval Click to select vour answer(s)Explanation / Answer
solution:-
given mean = 98.50 , standard deviation = 0.67
formula = sqrt((n-1)*s^2)/x^2R < ? < sqrt((n-1)*s^2)/x^2L
=> we know that df = 104 - 1 = 103
= confidence is 0.10
x^2R = 121.8 , x^2L = 85.09
by that
=> sqrt((103)* 0.4489)/121.8) < ? < sqrt((103)*0.4489)/85.09)
=> (0.62 , 0.74)
is it safe to conclude that the population standard deviation is less than 2.20
option A. this conclusion is safe because 2.20 is outside the confidence interval