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:- A.The independent variable is the input variable and should be represented by the x-axis.
Explanation:-
A. Correct.
B. Not correct.
<u>Reason</u>:- The independent variable is the input variable and should be represented by the x-axis.
C. Not correct.
<u>Reason</u>:- The dependent variable is the output variable and should be represented by y-axis.
D. Not correct.
<u>Reason</u>:-The dependent variable is the output variable and should be represented by y-axis.
Answer:
Option (b) is correct.
Area of rectangle is 36 units
We have,
⇒36=6×6
=2×3×3×2
=4×9
Hence, the sides of a rectangle are 4cm and 9cm
Perimeter =2(l+b)
=2(4+9)
=13×2
=26units
Answer:
D
Step-by-step explanation:
!5% is equivalent to 15 parts over the whole 100 part. It is written in proportions as 15/100.
Similarly, you need to find how many parts in 80 are equivalent to 15%or 15/100. So, just equate both equation with x as an unknown.
x/80 = 15/100
x = (15/100)*80
x = 12
Thus, the 15% of 80 is 12.