How much

Assignment 47791
Q 1.
Given the same sample statistics 75% level of confidence is narrower as for less level of confidence we are more precise for less accuracy so the margin of error will becomes less so the resulting confidence interval will also be less.
Q 2.
n = 10
sample mean = 63.4
population standard deviation = 2.4
c : level of confidence = 0.95
Zc : critical value = 1.96
ZC * Population standard deviation 1.96*2.4
E : Margin of error = --------------------------------------------------------- = ------------------- = 1.4875
Sqrt(n) sqrt(10)

Lower limit = sample mean – E = 63.4 – 1.4875 = 61.9125
Upper limit = sample mean + E = 63.4 + 1.4875 = 64.8875
So the confidence interval for mean is (61.9, 64.9) so option c is correct option.
Q. 3
N : population standard deviation = 800
N : sample size = 40
Sample mean = 130
Sample standard deviation = 10
C : level of confidence = 0.95
Finite population correction factor = sqrt ((N-n)/(N-1)) = 0.9753
Degrees of freedom = n – 1 = 39
E : margin of error = tc *s/sqrt(n)*finite population correction factor
= 2.045 * 10/sqrt(40)*0.9753
= 3.1538
Lower limit = sample mean – E = 130-3.1538 = 126.8
Upper limit = sample mean + E = 130+ 3.1538 = 133.2
So the confidence...