# Confidence Interval

What is the predicted value for x = 10, if the regression equation is:

y' = 106.8 - 3.1x?

If alpha/2 = 0.02, the confidence interval is the ______% confidence interval.

The Academy of Orthopedic Surgeons states that 80 out of every 100 women wear shoes that are too small for their feet. A researcher wants to be 98% confident that this proportion is within 2 units of the true number. From a previous study, the standard deviation is known to be 12 out of every 100. How large a sample is necessary?

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#### Solution Preview

predicted value is y= 106.8 - 3.1 * 10 = 75.8

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<br>If alpha/2 = 0.02, the confidence interval is the ______% confidence interval.

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<br>in this case, alpha=.04, so this is a 96% confidence interval.

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<br>The Academy of ...

#### Solution Summary

What is the predicted value for x = 10, if the regression equation is:

y' = 106.8 - 3.1x?

If alpha/2 = 0.02, the confidence interval is the ______% confidence interval.

The Academy of Orthopedic Surgeons states that 80 out of every 100 women wear shoes that are too small for their feet. A researcher wants to be 98% confident that this proportion is within 2 units of the true number. From a previous study, the standard deviation is known to be 12 out of every 100. How large a sample is necessary