Refrigerator A costs $600 and $50 per year for the electricity to operate it. Refrigerator B costs $1200 and $40 per year for th
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Answer:
The 99% confidence interval for the true population proportion of people with kids is (0.293, 0.547).
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 z-score that has a p-value of .
Out of 100 people sampled, 42 had kids.
This means that
99% confidence level
So , z is the value of Z that has a p-value of
, so
.
The lower limit of this interval is:
The upper limit of this interval is:
The 99% confidence interval for the true population proportion of people with kids is (0.293, 0.547).