5. Elon Musk and Anousheh Ansari are discussing the carbon removal competition. Both review the results of research work performed in the last 50 years and cannot agree that it will take only another 30 years to significantly reduce CO2 in the atmosphere and oceans. The results are below. Test at the 2% level of significance.

Only answers that show full calculations will be graded (not optional)

1990 2020

Sample Mean CO₂ (ppm) 353.34 385

Population Standard Deviation 33 40

a. State the H0:

b. State the Ha:

c. Is this a right-, left-, or two-tailed test?

d. State the distribution to use for the test

e. What is the test statistic?

f. What is the p-value?

g. Alpha:h. Decision:

i. Reason for decision:

j. What is the conclusion?