The Amount of Time Required for an Oil and Filter

question 78

Short Answer

The amount of time required for an oil and filter change on an automobile is normally distributed with a mean of 45 minutes and a standard deviation of 10 minutes.A random sample of 16 cars is selected.What is the probability that the sample mean will be between 39 and 48 minutes?

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Definitions:

T Distribution

A probability distribution that is used in hypothesis testing for small sample sizes, when the population standard deviation is unknown.

Normal Distribution

A probability distribution that is symmetric around the mean, showing that data near the mean are more frequent in occurrence than data far from the mean.

Confidence Interval

A range of values, derived from sample statistics, that is likely to contain the value of an unknown population parameter with a certain level of confidence.

Confidence Level

The probability or percentage that a parameter lies within a specified range of values, indicating the degree of certainty about a statistical estimate.