help with question 5 The cholesterol values for a certain po

The cholesterol values for a certain population arc approximately normally distributed with a mean of 200 mg/100 ml and a standard deviation of 20 mg/100 ml. Use the empirical rule to answer the following: What is the proportion that an individual picked at random from this population will have a cholesterol level between 200 and 240 mg/100 ml? What is the interval containing 95% of all cholesterol levels of this population? Suppose you were not confident that the cholesterol values were in fact normally distributed. What is then the interval containing at least 89% of all cholesterol levels of this population?

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