Question

Here is an SRS of values of city mpg for a particular model of car.

28.0	25.7	25.8	28.0	28.5	29.8	30.2	30.4
26.9	28.3	29.8	27.2	26.7	27.7	29.5	28.0

Suppose that the standard deviation is believed to be 0.5 mpg.

Compute a 99% confidence interval for the true city mpg for this model.

Use 1 decimal place accuracy.

The interval is ( ____ , ____ ) mpg.

What is the probability (as an integer percent) that the true city mpg of this car is not within your interval? ____%

The manufacturer claims that the city mpg of this model car is 31 miles per gallon.

Assuming your data was gathered and recorded accurately, which is more likely.

The mpg of this model car is not normally distributed.

You have an unusual sample.

The standard deviation is wrong.

The car company has overstated the city mpg for this car.

In fact, you can use the Central Limit Theorem to compute the probability of an SRS of 16 observations has a mean below 28.15 mpg if the true city mpg is 31.

The distribution of mean city mpg's of SRS's of size 16 will be approximately ____ with a mean of ____ and a standard deviation of ____ , so the probability of seeing an SRS of size 16 with mean below 28.15 is ____.

Answer 1

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