Question
A group of boys at GHS had their heights measured. The mean height was determined to be 68 inches with a standard deviation of 3 inches . If one of these boys is selected at random, what is the probability that he will be less than 65 inches tall? .34 .66 .84 .16
Solution
4.4
(290 Votes)
Leroy
Professional ยท Tutor for 6 years
Answer
### 0.16
Explanation
## Step 1: Calculate the z-score### The z-score measures how many standard deviations a data point is from the mean. It is calculated as:
, where
is the data point (65 inches),
is the mean (68 inches), and
is the standard deviation (3 inches). Therefore,
.## Step 2: Find the probability corresponding to the z-score### A z-score of -1 corresponds to a probability of 0.1587 (from a standard normal distribution table or calculator). This represents the probability of a randomly selected boy being shorter than 65 inches. Rounding to the nearest hundredth gives 0.16.