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Recently, an estate agent received complaints about the condition of several houses that he sold. The estate agent conducted an analysis and found that 5% of all houses that he sold are not in good condition after 2 years. A sample of 20 houses that he sold is selected at random. Let X be the number of houses in this sample which are not in good condition after 2 years. Find the mean and standard deviation for this distribution. (4 marks) E Calculate the probability that exactly 3 houses are not in good condition after 2 years. (2 marks)