This is Statistics. Answer what is required. Provide clean and clear Solutions

3. The manufacturer of a certain brand of auto batteries claims that the mean life of these batteries is 45 months. A consumer protection agency that wants to check this claim took a random sample of 36 such batteries and found that the mean life for this sample is 43.75 months with the standard deviation of 4 months. Using the 0.025 significance level, would you conclude that the mean life of these batteries is less than 45 months? Step 1. State the null hypothesis and alternative hypothesis: (Ho ) H Ha: Step 2. What is the level of significance ? Step 3. What is the critical value? Zt = Step 4. Compute the test - statistic value: Zc- Step 5. What is your decision rule? Step 6. What would be your conclusion based on the test-statistic value