Question

Use the table to answer the question. Note: Round z-scores to the nearest hundredth and then find the required A values using the table. A manufacturer of light bulbs finds that one light bulb model has a mean life span of 1025 h with a standard deviation of 88 h. What percent of these light bulbs will last as follows? (Round your answers to one decimal place.) (a) at least 940 h
(b) between 850 and 900 h ​

Answer 1

I think the answer us A b doesn’t adds up