Answer:
a) lower limit = 4.295 minutes
b) upper limit = 6.365 minutes
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 = 5.33 minutes
Standard deviation r = 1.33 minutes
Number of samples n = 11
Confidence interval = 99%
z(at 99% confidence) = 2.58
Substituting the values we have;
5.33+/-2.58(1.33/√11)
5.33+/-2.58(0.401010088288)
5.33+/-1.0346060277
5.33+/-1.035
= ( 4.295, 6.365) minutes
Therefore at 99% confidence interval (lower, upper limit) = ( 4.295, 6.365) minutes
a) lower limit = 4.295 minutes
b) upper limit = 6.365 minutes
