4.(A)For some value of Z, the value of the cumulative standardized normal distribution is0.2090. The value of Z is: A) – 0.81 B) – 0.31 C) 0.31 D) 1.965.(A)Given a standardized normal distribution with mean of 0 and a standard deviation of1, what is the probability that Z is less than ‐1.27 or greater than 1.74? (A) 0.1429 (B)0.9591 (C) 0.1093 (D)0.0409.6.( C)Which of the following about the normal distribution is not true? A) Theoretically,the mean, median, and mode are the same. B) About 2/3 of the observations fallwithin ±1 standard deviation from the mean. C) It is a discrete probabilitydistribution. D) Its parameters are the mean, μ, and standard deviation, σ.7.(C )Suppose X is a normal random variable with mean 18 and standard deviation 5. It isknown that P(X≤18.6)=0.5478; then, P(17.4