Answer:
Explanation:
If the mean is 30 and the standard deviation is 10, the probability that a value selected is greater than 50 can be found using the standard normal distribution.
The standard normal distribution has a mean of 0 and a standard deviation of 1, so we need to standardize the value of 50 by subtracting the mean of 30 and dividing by the standard deviation of 10.
z = (50 - 30) / 10 = 2
Next, we can look up the value of z = 2 in a standard normal distribution table, or use a calculator or software that has functions for normal distributions. The result represents the probability of a standard normal random variable being less than 2, so to find the probability of a value being greater than 50, we subtract this result from 1.
The probability of a value selected being greater than 50 is approximately 0.0228 or 2.28%.