The average number of words in a romance novel is 64,209 and the standard deviation is 17,495. Assume the distribution is normal. Let X be the number of words in a randomly selected romance novel....

The average number of words in a romance novel is 64,209 and the standard deviation is 17,495. Assume the distribution is normal. Let X be the number of words in a randomly selected romance novel. Round all answers to 4 decimal places where possible.


a. What is the distribution of X? X ~ N(,)


b. Find the proportion of all novels that are between 50,213 and 65,959 words.


c. The 90th percentile for novels is  words. (Round to the nearest word)


d. The middle 60% of romance novels have from words to words. (Round to the nearest word)

On average, indoor cats live to 14 years old with a standard deviation of 2.2 years. Suppose that the distribution is normal. Let X = the age at death of a randomly selected indoor cat. Round answers to 4 decimal places where possible.


a.  What is the distribution of X? X ~ N(,)


b. Find the probability that an indoor cat dies when it is between 9.3 and 11.1 years old.


c.  The middle 50% of indoor cats' age of death lies between what two numbers?
     Low:  years
     High:  years