The manager of a computer retails store is ooncemed that his suppliers have been giving him laptop oomputers with lower than average quality. His research shows that repLacement times for the model laptop of conoern are normally distributed with a mean of 3.9 years and a standard deviation of 0.6 years. He then randomly selects records on 36 laptops sold in the past and finds that the mean replacement time is 3.6 years. Assuming that the laptop repLacement times have a mean of 3.9 years and a standard deviation of 0.6 years, find the probability that 30 randomly selected laptops will have a mean replaoement time of 3.6 years or less. PM 5 3.6 years] = C] Enter your answer as a number accurate to 4 decimal places. NUT E: Answers obtained using exact zscores or zsoores rounded to 3 decimal places are accepted. Based on the result above, does it appear that the computer store has been given laptops of lower than average quality? D Tbs. The probability of this data is unlikely to have occurred by chance alone. D No. The probability of obtaining this data is high enough to have been a chance occurrence. A company produces steel rods. 111e lengths of the steel rods are normally distributed with a mean of 192.1-cm and a standard deviation of 2.5-cm. For shipment, 12 steel rods are bundled together. Find PE, which is the average length separating the smallest 2536 bundles from the Largest 36% bundles. Enter your answer as a number accurate to 2 decimal place. Answers obtained using exact z-scores or z- scores rounded to 3 decimal places are acoepted. The amounts of nicotine in a certain brand of cigarette are normally distributed with a mean of 0.913 g and a standard deviation of 0.295 g. The company that produces these cigarettes claims that it has now reduced the amount of nicotine. The supporting evidence consists of a sample of 39 cigarettes with a mean nicotine amount of 0.861 g. Assuming that the given mean and standard deviation have NOT changed, find the probability of randomly seleting 39 cigarettes with a mean of 0.861 g or less. P(M