Answer: 
Step-by-step explanation:
Given : Sample size : 
Sample mean : 
Standard deviation : 
Significance level : 
Critical value : 
Formula to find the confidence interval for population mean :-

Hence, a 90% confidence interval estimate of the population mean of all students = 
B and C because sqrt of 16=4 so sqrt of anything larger than 16 is greater than 4
This is a perfect square trnomial
(a+b)²=a²+2ab+b²
we see that a=5x and b=2
(5x)²+2(5x)(2)+2²=0
factor
(5x+2)²=0
set equal to zero
5x+2=0
5x=-2
x=-2/5
Answer:
(3X8) - 4 + 2 - 12
Step-by-step explanation:
Following the order of operations solve:
(24) - 4 + 2 - 12
20 + 2 - 12
22 - 12
10
Don't feel bad, this is an odd question and the parenthesis do not seem to be required. Following the order of operations would result in the same answer anyway...
Odd.
Of means multiplication and Is means equals. So 0.81x =405
X = 500