For a standard normal random variable Z, what is approximately P(−1 < Z < 1)?
Correct answer: C. 0.6826
- A. 0.3413
- B. 0.5000
- C. 0.6826
- D. 0.9544
Explanation
The central interval from one standard deviation below the mean to one above the mean contains about 68.26 percent of a normal distribution. The value 0.9544 corresponds approximately to the interval from −2 to 2.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
Practise Probability and Probability Distributions
30 free Probability and Probability Distributions MCQs from Quantitative Methods, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Quantitative Methods questions like this
Quantitative Methods is on this paper prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for it.
More Probability and Probability Distributions questions
A box contains 6 defective and 14 nondefective items. If 3 items are selected without replacement, what is the probability that exactly 1 is defective?
If X follows a Poisson distribution with parameter λ = 2, what is P(X = 2)?
If X follows a binomial distribution with n = 10 and p = 0.4, what is Var(X)?
A continuous random variable is uniformly distributed on the interval from 4 to 10. What is its expected value?
Which condition is required for a binomial probability model?
A random variable X has probability density function f(x) = 1/6 for 0 ≤ x ≤ 6 and f(x) = 0 otherwise. What is P(2 ≤ X ≤ 5)?