Question

An SRS of 27 students at UH gave an average height of 5.6 feet and a standard deviation of 1 feet. Construct a 90% confidence interval for the mean height of students at UH.

a) [5.567, 5.633]
b) [5.429, 5.771]
c) [5.594, 5.606
d) [4.350, 7.050]
e) [4.100, 7.400]
f) None of the above

Answer 1

Answer: f) None of the above

= ( 5.283, 5.917)

Therefore at 90% confidence interval (a,b) = ( 5.283, 5.917)

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 = 5.6ft

Standard deviation r = 1.0ft

Number of samples n = 27

Confidence interval = 90%

z(at 90% confidence) = 1.645

Substituting the values we have;

5.6+/-1.645(1.0/√27)

5.6+/-1.645(0.192)

5.6+/-0.317 ft

= ( 5.283, 5.917)

Therefore at 90% confidence interval (a,b) = ( 5.283, 5.917)