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
Shipment = 72 cases of books + 94 cases of magazines
1 case of books = 35 pounds
1 case of magazines = 23 pounds
Shipment = 72 × 35 + 94 × 23 pounds
72 × 35 = 2520
94 × 23 = 2162
Shipment = 2520 + 2162 pounds
Shipment = 4682 pounds
angle QRP=180-(64+47)
=69°
Using sin rule,
p/sinP=q/sinQ.
7.6/sin64=q/sin47
q=6.2cm
Using the formula;
area=1/2p*qsinR
we have;
1/2×7.6×6.2×sin69°=21.995
answer= 22
A proportional relationship is also a direct variation.
The general equation of direct cvariation is
y = kx,
where k is a number.
In your case, if k = -1, then y = kx becomes y = (-1)x which is the same as
y = -x
