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.
Answer:A
Step-by-step explanation: In exponents,
a
1
m
=
m
√
a
Hence
x
1
2
=
2
√
x
Answer:
70°
Step-by-step explanation:
ABC is the center angle that sees the arc and is twice as angle ADC so the measure of ABC is e × 35 = 70
Answer:
- x=8, x=2
- no solution
- no solution
Step-by-step explanation:
For the equation ...
y = a(x -h)² +k
you can find the x-intercepts by setting y=0 and solving for x.
0 = a(x -h)² +k
-k = a(x -h)² . . . . . . subtract k
-k/a = (x -h)² . . . . . divide by a
±√(-k/a) = x -h . . . . take the square root
h ± √(-k/a) = x . . . . add h . . . . this is the general solution
__
So, for each of your problems, fill in the corresponding numbers and do the arithmetic. If (-k/a) is a negative number, the square root gives imaginary values, so there is "no solution".
1. x = 5 ± √9 = {5 -3, 5 +3} = {2, 8} . . . . the x-intercepts are 2 and 8
2. x = -3 ± √(-2) . . . . . . no solution; the roots are complex
3. x = 5 ± √(-8/4) . . . . . no solution; the roots are complex