Question

Z is a standard normal random variable (normally distributed data). The P(-1.96 ≤ z ≤ -1.4) equals

Answer 1

Since, Z is a standard normal variate, the = 0.0808 - 0.0250

= 0.0558

[The is the area under the z curve on the left side of z = -1.4 and can be obtained from the z table corresponding to the value of z = -1.4 at 0.00 probability and is equal to 0.0808.

Similarly, is the area under the z curve on the left side of z = -1.96 and can be obtained from the z table corresponding to the value of z = -1.9 at 0.06 probability and is equal to 0.0250]