Answer:
55+/-3.69
= (51.31, 58.69)
Therefore, the 99% confidence interval (a,b)= (51.31, 58.69)
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 =55
Standard deviation r = 10
Number of samples n = 49
Confidence interval = 99%
z-value (at 99% confidence) = 2.58
Substituting the values we have;
55+/-2.58(10/√49)
55+/-2.58(1.428571428571)
55+/-3.685714285714
55+/-3.69
= (51.31, 58.69)
Therefore, the 99% confidence interval (a,b)= (51.31, 58.69)