ALL ABOUT STATS

Instruction: Answer the following scenario using the six steps discussed in the module. Show your solutions. 1. An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a mean of 800 hours and a standard deviation of 40 hours. Test the hypothesis that u = 800 hours against the alternative u # 800 hours if a random sample of 30 bulbs has an average life of 788 hours. Use a 0.05 level of signifi- cance Step 1: Step 2: Step 3: Step 4: Step 5: Step 6:2. The average height of females in the freshman class of a certain college has been 162.5 cm with a standard deviation of 6.9 cm. Is there reason to believe that there has been a change in the average height if a random sample of 50 females in the present freshman class has an average height of 165.2 cm? Use a 0.01 level of significance. Step 1: Step 2: Step 3: Step 4: Step 5: Step 6