Answer:
Now we just take square root on both sides of the interval and we got:
And the best option would be:
A. 2.2 < σ < 2.8
Step-by-step explanation:
Information provided
represent the sample mean
population mean
s=2.4 represent the sample standard deviation
n=83 represent the sample size
Confidence interval
The confidence interval for the population variance is given by the following formula:
The degrees of freedom are given by:
The Confidence is given by 0.90 or 90%, the value of 
and 
, the critical values for this case are:
And replacing into the formula for the interval we got:
Now we just take square root on both sides of the interval and we got:
And the best option would be:
A. 2.2 < σ < 2.8
Answer:
5x+32=45;x=2.6
Step-by-step explanation:
5x+17+15=45
5x+32=45
5x=13
x=2.6
Answer: 2 3/4 > 2.68 is correct (only)
Step-by-step explanation: 2 3/4 = 2.75, and 2.75 is greater than 2.68
The rest are incorrect. 7.895 * 10^2 (100) = 789.5, and 5.43 * 10^3 (1000) = 5430. So 789.5 > 5430 is false.
Sqrt(63) = 7.93, and 7.93 > 8.11 is false.
Absolute values ( | | ) mean that no matter if it is negative or positive, it will become positive (unless the negative sign is outside the absolute value). 1.5 > 3.2 is false, and even without the absolute value, -1.5 is still less than 3.2
-4x +12 -12 = -4 -12
-4x = -16
x = 4
