Answer:
7.1+/-0.48
= (6.62, 7.58) hours
Therefore, the 95% confidence interval (a,b)= (6.62, 7.58) hours
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 = 7.1 hours
Standard deviation r = 0.78 hour
Number of samples n = 10
Confidence interval = 95%
z value(at 95% confidence) = 1.96
Substituting the values we have;
7.1+/-1.96(0.78/√10)
7.1+/-1.96(0.246657657493)
7.1+/-0.483449008686
7.1+/-0.48
= (6.62, 7.58) hours
Therefore, the 95% confidence interval (a,b)= (6.62, 7.58) hours