Answer:
A sample size of 79 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of
.
For this problem, we have that:

The margin of error is:
95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
What sample size is needed if the research firm's goal is to estimate the current proportion of homes with a stay-at-home parent in which the father is the stay-at-home parent with a margin of error of 0.09?
A sample size of n is needed.
n is found when M = 0.09. So






Rounding up to the nearest whole number.
A sample size of 79 is needed.
1) No. 28/21 does not end up being equal to 2.
2) No. 45/5 does not equal 18/2
3) No. For something to be proportional, it should at least have the smaller number in the same place.
4) No. 25/12 does not equal 53/40
5) Yes. 4/2 is equal to 14/7
6) Yes. 4/1 is equla to 12/3
7) No. For something to be proportional, it should at least have the smaller number in the same place.
8) No. 44/9 is not equal to 36/11
9) Yes. 10/5 is equal to 16/8
10) Yes. 24/12 is equal to 14/7
11) No. 24/4 is not equal to 42/9
12) Yes. Both equal 1.
13) Yes. 20/5 is equal to 44/11
14) No. 44/40 is not equal to 34/30
15) Yes . 40/4 is equal to 10/1
16) Yes. 36/4 is equal to 45/5
17) No. 16/2 is not equal to 13/1
18) No. 38/9 is not equal to 28/7
19) Yes. This is a common proportion.
20) Yes. 50/25 is equal to 2.
21) Yes. 36/24 is equal to 3/2.
22) Yes. 18/12 is equal to 42/28
23) No. 33/42 is not equal to 27/37
24) No. 34/7 is not 4
25) Yes. The second proportion listed is half of the first
26) Yes. This is proportional.
27) Yes. This is proportional.
28) Yes. This is proportional.
29) No. This is not proportional.
30) No. This is not proportional
31) Yes. This is proportional.
32) Yes. This is proportional
33)
34)
35)
36)
37)
38)
39)
40)
I hope this helped. I left the last few unsolved so you could follow the patterns to find them out!
Answer:
Range of F(x) = (-∞ ,72).
Step-by-step explanation:
Range of the function F(x) means the set of values which are taken by the function along its domain.
F(x) = 72 - 
Since coefficient of
is negative on the right side ,
Maximum value of F(x) will come at x = 0.
Which is, F(0) = 72.
Now, as x increases , F(x) decreases , when x will reach infinity ,
F(x) will be reaching negative of infinity .
Thus, F(x) is ranging from -∞ to 72 .
Range of F(x) = (-∞ ,72).