Given a normally distributed random variable X with a µ=5 and σ=2, find P(X>8).Question 2Answera.0.0001b.0.9270c.0.1862d.0.0668
Question
Given a normally distributed random variable X with a µ=5 and σ=2, find P(X>8).
Question 2 Answers:
a. 0.0001
b. 0.9270
c. 0.1862
d. 0.0668
Solution
To find the probability that a normally distributed random variable X is greater than 8 (P(X>8)), we first need to standardize this value using the Z-score formula:
Z = (X - µ) / σ
where: X is the value we are interested in (in this case, 8), µ is the mean of the distribution (in this case, 5), and σ is the standard deviation of the distribution (in this case, 2).
Substituting these values into the formula, we get:
Z = (8 - 5) / 2 = 1.5
Next, we look up this Z-score in a standard normal distribution table, or use a calculator or software that can compute it. The value we get from the table is the probability that the variable is LESS than our value. But we want the probability that it is MORE than our value. So we subtract the value from 1.
The value for Z=1.5 is approximately 0.9332. So, P(X>8) = 1 - 0.9332 = 0.0668.
So, the answer is d. 0.0668.
Similar Questions
Given a normally distributed random variable X with a µ=5 and σ=2, find the 30th percentile.Question 4Answera.1.24b.2.41c.3.95d.6.05
Given a normally distributed random variable X with a µ=5.3 and σ=2.1, find 90th percentile.Question 2Answera.8.89b.7.07c.7.99d.4.32
Suppose a normal distribution has a mean of 98 and a standard deviation of 6. What is P(x ≥ 86)?
Assume that the random variable X is normally distributed with mean μ = 120 and standard deviation σ = 13. Find P(110 < X < 145).
Suppose a normal distribution has a mean of 79 and a standard deviation of 7. What is P(x ≥ 93)?A.0.025B.0.16C.0.84D.0.975SUBMITarrow_backPREVIOUS
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.