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:
12 hours
Step-by-step explanation:
Let the number of hours be represented as h.
Sarah's surfboards charges a fee of $60 to rent a surfboard and then $10.50 per hour.
Mathematically ,
60 + 10.50h
Sally's surfboards does not charge a fee, but they cost $15.50 per hour
Mathematically,
15.50h
Equating both equations together
60 + 10.50h = 15.50 h
Collect like terms
60 = 15.50h - 10.50h
60 = 5h
h = 60/5
h = 12 hours
Therefore, the number of hours that the cost will be the same to rent a surfboard for each shop is 12 hours.
Answer: x = 7 and y = -17
Step-by-step explanation:
Opposite sides of parallelograms are equal.
-5y + 3 = 88
-5y = 85
y = -17
10x - 7 = 63
10x = 70
x = 7
Answer:
FCD
Step-by-step explanation: and sometimes we do not care about bold writing
FCD is the vertical angle I guess.
okay.
Answer:
$33
Step-by-step explanation:
Given: Addy had 20% off coupon.
The coupon took $8.25 off of the shirt price.
Lets assume the original cost of shirt be "x".
We know Addy had 20% off coupon, which help to reduce the price of shirt by $8.25.
∴ We can form an equation to know the original price of shirt.
⇒
⇒
Multiplying both side by 5
⇒
∴ 
Hence, The original cost price of shirt was $41.25.
Next, finding the price paid by Addy for her new shirt by reducing coupon discount from the cost of shirt.
Price paid by Addy for her new shirt= 
Hence, Addy paid $33 for her new shirt.