Answer:
CI for 90% = ( 16.34, 18.66)
Therefore at 90% confidence interval (a,b) = ( 16.34, 18.66)
And,
CI for 95% = ( 16.11, 18.89)
Therefore at 95% confidence interval (a,b) = ( 16.11, 18.89)
Step-by-step explanation:
Answer: = ( 2.64, 3.14)
Therefore at 95% confidence interval (a,b) = ( 2.64, 3.14)
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 = 17.5
Standard deviation r = 5.7
Number of samples n = 65
Confidence interval = 90% and 95%
z(at 90% confidence) = 1.645
z(at 95% confidence) = 1.96
Substituting the values we have; for 90%
17.5+/-1.645(5.7/√65)
17.5+/-1.645(0.707)
17.5 +/- 1.16
= ( 16.34, 18.66)
Therefore at 90% confidence interval (a,b) = ( 16.34, 18.66)
Substituting the values we have; for 95%
17.5+/-1.96(5.7/√65)
17.5+/-1.96(0.707)
17.5 +/- 1.39
= ( 16.11, 18.89)
Therefore at 95% confidence interval (a,b) = ( 16.11, 18.89)
