What is set of natural numbers less than 10
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Which of the following contains a variable?

If f(x) = 4x - 3 and g(x) = x + 4, find (f - g) (x)

The patient recovery time from a particular surgical procedure is normally distributed with a mean of 5.2 days and a standard deviation of 1.7 days. what is the probability of spending more than 2 days in recovery? (round your answer to four decimal places.)