Question

find the area under the standard normal curve to the right of z = - 1.25.

a. 0.5843
b. 0.7193
c. 0.6978
d. 0.8944

Explanation:

Step1: Recall the property of standard normal curve

The total area under the standard - normal curve is 1. The area to the left of a z - score $z$ is given by $\Phi(z)$ from the standard normal table. We want $P(Z > - 1.25)$.

Step2: Use the complement rule

We know that $P(Z > - 1.25)=1 - P(Z\leq - 1.25)$. Looking up the value of $P(Z\leq - 1.25)$ in the standard - normal table, we find that $P(Z\leq - 1.25)=0.1056$.

Step3: Calculate the required area

$P(Z > - 1.25)=1 - 0.1056 = 0.8944$.

Answer:

D. 0.8944