Suppose that Apple Inc. wished to estimate the mean time people spend on their phones every...

Suppose that Apple Inc. wished to estimate the mean time people spend on their phones every day. In a random sample of 30 phones users the mean time was found to be 150 minutes with a standard deviation of 70 minutes.

* Construct a 90% confidence interval for the mean time people spend on their phone every day.

* Construct a 95% confidence interval for the mean time people spend on their phone every day.

* Construct a 99% confidence interval for the mean time people spend on their phone every day.

*As you increased the level of confidence what happens to the the width of your confidence intervals?

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Expert Solution

orchestra answered 2 years ago

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