QUESTION 1 Suppose that the number of movies people rent per month is normally distributed with a mean of 4.8 and a standard deviation of 1.5. What is the probability that in a random sample of 50 people that the average number of movies they rented last month is greater than 4.5 ? (please round your answer to 4 decimal places)
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To find the probability that the average number of movies rented by a sample of 50 people is greater than 4.5, we can use the Central Limit Theorem. First, we determine the standard error (SE) of the sample mean using the formula: \[ SE = \frac{\sigma}{\sqrt{n}} = \frac{1.5}{\sqrt{50}} \approx 0.2121. \] Next, we convert the sample mean to a z-score: \[ z = \frac{\bar{x} - \mu}{SE} = \frac{4.5 - 4.8}{0.2121} \approx -1.414. \] Now, we can find the probability that the sample mean is greater than 4.5 by looking up the z-score in the standard normal distribution table. The probability \( P(Z > -1.414) \) is approximately 0.9216. Therefore, the probability that the average number of movies rented by a random sample of 50 people is greater than 4.5 is approximately **0.9216** (rounded to four decimal places).