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5. A study found that the average time it took a person to find their dream home was 5.9 months. If a sample of
36 people were surveyed, find the 95% confidence interval of the mean. Assume the standard deviation of
the population is 0.8 month.

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Answer:

The 95% confidence interval of the mean time it took a person to find their dream home is between 5.64 months and 6.16 months.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1-0.95}{2} = 0.025[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].

So it is z with a pvalue of [tex]1-0.025 = 0.975[/tex], so [tex]z = 1.96[/tex]

Now, find the margin of error M as such

[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 1.96\frac{0.8}{\sqrt{36}} = 0.26[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 5.9 - 0.26 = 5.64 months

The upper end of the interval is the sample mean added to M. So it is 5.9 + 0.26 = 6.16 months.

The 95% confidence interval of the mean time it took a person to find their dream home is between 5.64 months and 6.16 months.