Question

You measure 49 textbooks' weights, and find they have a mean weight of 54 ounces. Assume the population standard deviation is 11.7 ounces. Based on this, construct a 95% confidence interval for the true population mean textbook weight. Use z = 2 for calculations

Answer 1

Answer:

= ( 50.66, 57.34)

Step-by-step explanation:

Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.

The confidence interval of a statistical data can be written as.

x+/-zr/√n

Given that;

Mean x = 54 ounces

Standard deviation r = 11.7 ounces

Number of samples n = 49

Confidence interval = 95%

z(at 95% confidence) = 2

Substituting the values we have;

54+/-2(11.7/√49)

54+/-2(1.671428571428)

54+/-3.342857142857

54+/-3.34

= ( 50.66, 57.34)

Therefore, the 95% confidence interval (a,b)

= ( 50.66, 57.34)

Thanks