Answer:
atleast 385
Step-by-step explanation:
Given that an electrical power company is looking to expand into a new market. Before they commit to supplying the new area with electricity, they would like know the mean daily power usage for homes there.
Population std deviation = 
Sample size =
STd error of sample mean = 
Margin of error for 95% would be Critical value ( std error)
Here since population std dev is known we can use Z critical value= 1.96

Sample size should be atleast 385
Answer:
h(8q²-2q) = 56q² -10q
k(2q²+3q) = 16q² +31q
Step-by-step explanation:
1. Replace x in the function definition with the function's argument, then simplify.
h(x) = 7x +4q
h(8q² -2q) = 7(8q² -2q) +4q = 56q² -14q +4q = 56q² -10q
__
2. Same as the first problem.
k(x) = 8x +7q
k(2q² +3q) = 8(2q² +3q) +7q = 16q² +24q +7q = 16q² +31q
_____
Comment on the problem
In each case, the function definition says the function is not a function of q; it is only a function of x. It is h(x), not h(x, q). Thus the "q" in the function definition should be considered to be a literal not to be affected by any value x may have. It could be considered another way to write z, for example. In that case, the function would evaluate to ...
h(8q² -2q) = 56q² -14q +4z
and replacing q with some value (say, 2) would give 196+4z, a value that still has z as a separate entity.
In short, I believe the offered answers are misleading with respect to how you would treat function definitions in the real world.
<h2>
Answer:</h2>
The value of y is 8.4375
<h2>
Step-by-step explanation:</h2><h3>Known :</h3>
<h3>Asked :</h3>
- The value of y when x is 2.25
<h3>Solution :</h3>
2/7.5 = 2.25/y
Do a cross multiplication,
2/7.5 = 2.25/y
=> 20/75 = 2.25/y
=> 75 . 2.25 = 20y
=> 168.75 = 20y
Reverse the equation,
168.75 = 20y
=> 20y = 168.75
Find the value of y,
20y = 168.75
=> y = 8.4375
<h3>Conclusion :</h3>
y = 8.4375