Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 7.5 parts/million (ppm). A researcher believes that the current ozone level is not at a normal level. The mean of 24 samples is 7.8 ppm with a standard deviation of 0.7. Assume the population is normally distributed. A level of significance of 0.02 will be used. Find the value of the test statistic. Round your answer to three decimal places.

The value of the test statistic is

Step-by-step explanation:

Our test statistic is:

In which X is the sample mean, is the expected value, is the standard deviation and n is the size of the sample.

The level of ozone normally found is 7.5 parts/million (ppm).

This means that

The mean of 24 samples is 7.8 ppm with a standard deviation of 0.7.

This means that

Test Statistic:

The value of the test statistic is

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step-by-step explanation: