The heights of a certain type of tree are approximately normally distributed with a mean height mu is equal to 5 ft and a standard deviation sigma is equal to 0 point 4 ft. Which statement must be true?

To find how many standard deviations a height is from the mean, subtract the mean height, 5 ft, and divide by the standard deviation, 0.4 ft. For a height of 6.2 ft, (6.2 − 5) ÷ 0.4 = 3, so it is 3 standard deviations above the mean. The statement that a 6.2-ft tree is 3 standard deviations above the mean is correct.

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