# Normal Probability Distribution and Confidence Intervals

What is the probability of P(-1.4 < Z < 0.6)?

In a standard normal distribution, what is the area which lies between Z = -1.72 and

Z = 2.53?

Use the following information to conduct the confidence intervals specified to estimate μ.

95% confidence; X ̅=25, σ^2= 12.25, and n=60.

30% confidence; X ̅=119.6, S^2= 570.7321, and n=75

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#### Solution Preview

Hi there,

P(-1.4<z<0.6)=P(z<0.6)-P(z<-1.4)=0.7257-0.0808=0.6449

area which lies between z=-1.72 and z=2.53: ...

$2.19