Answer:
what is the question
Step-by-step explanation:
Answer: = ( 63.9, 66.7)
Therefore at 90% confidence interval (a,b)= ( 63.9, 66.7)
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 = 65.3
Standard deviation r = 5.2
Number of samples n = 36
Confidence interval = 90%
z(at 90% confidence) = 1.645
Substituting the values we have;
65.3 +/-1.645(5.2/√36)
65.3 +/-1.645(0.86667)
65.3+/- 1.4257
65.3+/- 1.4
= ( 63.9, 66.7)
Therefore at 90% confidence interval (a,b)= ( 63.9, 66.7)
