Answer:
$393.50+/-$19.72
= ( $373.78, $413.22)
Therefore, the 95% confidence interval (a,b) = ($373.78, $413.22)
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 = $393.50
Standard deviation r = $50.30
Number of samples n = 25
Confidence interval = 95%
z value(at 95% confidence) = 1.96
Substituting the values we have;
$393.50+/-1.96($50.30/√25)
$393.50+/-1.96($10.06)
$393.50+/-$19.7176
$393.50+/-$19.72
= ( $373.78, $413.22)
Therefore, the 95% confidence interval (a,b) = ($373.78, $413.22)
Step-by-step explanation:
4 times = 4x increased by 7 = 4x+7

Answer:
A) 96 + x ≤ 149
Step-by-step explanation:
The airplane can hold 149 passengers.
There are already 96 passengers on board.
They can add x additional passengers, as long as they bring the total to no more than 149.
The inequality is
96 + x ≤ 149
Su is the only child under 12 years of age, therefore, she is only child entering for free.