A building manager installs sensors to see how often people turn of the lights when they leave a room. After a month the manager has sample size of 625, a sample mean of 47%, and a sample standard deviation of 5%. What is the confidence level for a confidence interval of 46.8% to 47.2%?

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dude · Answer

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Okay so we first have to understand what standard deviation is and how confidence interval works

If the data is 1 standard deviation away from the mean from either side, we would be 68% confident of our data

If the data is 2 standard deviations away from the mean from either side, we would be 95% confident

If the data is 3 standard deviations away from the mean from either side, we would be 99% confident

dude · Answer

We know that the standard deviation is 5%
The mean is 47%

1 standard deviation is from 42-52%

However this range does not appear on our data interval so we would need to find the z-score

dude · Answer

Also, your answer choices are missing