Question

Assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of 0 and a standard deviation of 1. Find the probability that a given score is less than -1.21

Answer 1

Using a standard normal distribution table or calculator, the probability that a given score is less than -1.21 is approximately 0.1112.

Explanation:

The standard normal distribution has a mean of 0 and a standard deviation of 1, and it is a continuous probability distribution that ranges from negative infinity to positive infinity. To find the probability that a given score is less than -1.21, we need to calculate the area under the standard normal curve to the left of -1.21.

Using a standard normal distribution table or calculator, we can look up the area corresponding to a z-score of -1.21, which is approximately 0.1112. This means that the probability that a given score is less than -1.21 is approximately 0.1112, or 11.12%.

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