Answer:
$550+/-$20.79
= ( $529.21, $570.79)
Therefore, the 95% confidence interval (a,b) = ( $529.21, $570.79)
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 = $550
Standard deviation r = $75
Number of samples n = 50
Confidence interval = 95%
z(at 95% confidence) = 1.96
Substituting the values we have;
$550+/-1.96($75/√50)
$550+/-1.96($10.60660171779)
$550+/-$20.7889393668
$550+/-$20.79
= ( $529.21, $570.79)
Therefore, the 95% confidence interval (a,b) = ( $529.21, $570.79)
