In: Statistics and Probability
What is the probability that Z is less than minus − 0.27 0.27 or greater than the mean? The probability that Z is less than minus − 0.27 0.27 or greater than the mean is 0.8936
Solution:
We have to find the probability that z is less than -0.27 or greater than mean.
For Normal distribution or for standard normal distribution, probability of z less than mean or probability that z is greater than mean is always half or 0.5.
Thus the probability that z is greater than mean=0.5
Now we will find probability that z is less than -0.27.
That is P (z<-0.27)=....?
Look in z table for z=-0.2 and 0.07 and find corresponding area.
From above table we can see area corresponding to -0.2 and 0.07 is 0.3936
Thus the probability that z is less than -0.27 or greater than mean is:
P( z < -0.27 or z > mean)=0.3936+0.5=0.8936