Question

Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 7.6 parts/million (ppm). A researcher believes that the current ozone level is at an excess level. The mean of 1060 samples is 7.7 ppm. Assume a population standard deviation of 1.2. Does the data support the researcher's claim at the 0.02 level?

step 1 of 5 : State the null and alternative hypotheses.

Step 2 of 5 :  Find the value of the test statistic. Round your answer to two decimal places.

Step 3 of 5 : Specify if it is one tailed or two tailed

Step 4 of 5 :  Find the P-value of the test statistic. Round your answer to four decimal places.

Step 5 of 5 : Make the decision to reject or fail to reject the null hypothesis.

Answer 1

Step 1: Here claim is that current ozone level is at an excess level.

So hypothesis is vs

Step 2: As population standard deviation is known so we will use z statistics

Step 3: As alternative hypothesi is greater than hence it is one tailed test

Step 4: P value is

Step 5: As P value is less than alpha=0.02, we reject the null hypothesis

Hence we have sufficient evidence to support the claim that current ozone level is at an excess level