Question

For a standard normal distribution, which of the following expressions must always be equal to 1?
OP(z≤-a)-P(-a≤z≤a)-P(z≥a).
OP(z≤-a)-P(-a≤z≤a)+P(z≥ a)
OP(z≤-a)+P(-a≤z≤a)-P(z≥a)
OP(z≤-a)+P(-asz≤a)+P(zza)

Answer 1

Option D, For a standard normal distribution, the expression that is always equal to 1 is P(z ≤ -a) + P(-a≤z≤a) + P(Z≥a).

What is standard normal distribution?

A standard normal distribution is a normal distribution with a mean of zero and standard deviation of 1.

For a standard normal distribution, the total area of a curve is always equal to 1.

total area = P(z≤-a)+P(-a≤z≤a)+P(Z≥a) = 1

Thus, for a standard normal distribution, the expression that is always equal to 1 is P(z ≤ -a) + P(-a≤z≤a) + P(Z≥a).

Learn more about standard normal distribution here: https://brainly.com/question/4079902

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