Answer:
A sample of 179 is needed.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
That is z with a pvalue of
, so Z = 1.44.
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
A previous study found that for an average family the variance is 1.69 gallon?
This means that 
If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?
A sample of n is needed, and n is found for M = 0.14. So






Rounding up
A sample of 179 is needed.
Answer:
Just multiply the number by the percentage.
Step-by-step explanation:
1. Make the percentage into a decimal (%50= 0.50)
2. Multiply the decimal by the number.
Answer:
$60
Step-by-step explanation:
Movieland is in yellow....at the far left the Moviland- yellow 'regular' price for a DVD is shown as y= $20
three of these would be 3 x $20 = $60
Answer:
x = 3
Step-by-step explanation:
5x - 8 + 8 = 7 + 8
5x = 15
5x/5 = 15/5
15 divided by 5 equals 3
Hope this helped you out :)