Question

Find the area of the shaded region. The graph depicts the standard normal distribution of bone density scores with mean 0 and standard deviation 1 z=-0.86 z=1.21 The area of the shaded region is □ (Round to four decimal places as needed.)

Answer 1

Answer

we have to find the value of area or the probability when z is greater than -0.86 and less than 1.21

Using the formula

setting the values, we get

....equation 1

using z distribution table (looking 1.0 on left most column and 0.21 on top most row and selecting the intersection of column and row)

we get  

Similarly,using z distribution table , we can write setting the values in equation 1, we get

this gives us

So, area of shaded region is 0.6920 (rounded to four decimals)