Answer:
B. 10,368 square yards
Step-by-step explanation:
120x90= 10800
24x18=432
10800-432= 10,368 square yards
Answer:
14 km
Step-by-step explanation:
6 km in the afternoon
x km in the morning
6= x- 25%
6= 0.75x
x= 6/0.75
x= 8 km
total 6+8= 14 km
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:
What is the exact value of tan(−π4)? is 20
Answer:
-8 feet
Step-by-step explanation:
63 - 71 = -8