You measure 43 randomly selected textbooks' weights, and find they have a mean weight of 75 ounces. Assume the population standard deviation is 12.4 ounces. Based on this, construct a 90% confidence interval for the true population mean textbook weight.

by the empirical rule, 95% of the population is within 2 standard deviations of the mean

55 + or - 2(9.2) = 55+ or - 18.4 = (36.6,73.4)

95% of the population falls between 36.6 and 73.4 ounces

Step-by-step explanation:

56.6

step-by-step explanation:

the ratio of the perimeters is equal to the scale.

the ratio of the areas is equal to the square of the scale.

34 / 20 = k

a / 19.6 = k²

substituting:

a / 19.6 = (34 / 20)²

a = 19.6 (34 / 20)²

a ≈ 56.6

77

step-by-step explanation: