Answer:
2401
Step-by-step explanation:
Given that we want to estimate average income in a population.
The standard deviation of income in the population is $1,000
We want confidence interval around our estimate to be +/- $40
i.e Margin of error = 40
We know that margin of error = Std error * Z critical for 95%
i.e. 
Std error = 
Together we get
This is an answer I wrote last year check it out I have it in my progress
Answer:
Option D <em>The pattern is multiplicative because the earnings are 12 times the number of hours worked in each pair of values </em>is correct option.
Step-by-step explanation:
At x-axis we have number of hours worked and y-axis represents earnings in dollars.
We can make the table:
Number of hours worked (x) earnings in dollars (y)
1 12
2 24
3 36
4 48
5 60
Now, we need to find the pattern.
If we add 1+ 11 we get 12, but if we add 2+ 11 we get 13 and not 24 so, the pattern is not additive.
Now, if we multiply 1 by 12 (1 x 12) we get 12,
then 2 x 12 = 24
3 x 12 = 36
4 x 12 = 48
and 5 x 12 = 60
The same number if multiplied with x-axis we get y-axis.
So, the pattern is multiplicative. and we are multiplying 12 with the number of hours worked, so the correct option is option D.
Option D <em>The pattern is multiplicative because the earnings are 12 times the number of hours worked in each pair of values </em>is correct option.
Answer:
z = 0.9778x^2 / y.
Step-by-step explanation:
When z varies with the square of x the equation is z = kx^2 where k = a constant.
If it also varies inversely with y the equation is z = kx^2/y.
When z = 4.4 , x = 3 and y = 2 we have:-
4.4 = k * 3^2 / 2
Multiplying by 2:
8.8 = 9k
k = 8.8 / 9
= 0.9778.
So the required formula is z = 0.9778x^2 / y.
