Question 1155444
area to the left of 21 is 1/2, since that is the mean
z=(x-mean)/sd
=(19-21)/9 or -2/9.The area left of z=-2/9 is 0.412
to the right of 20 is area to the right of z=-1/9 or 0.544

to the right of 23 is the area to the right of z=2/9 or 0.412, the same as the area to the left of 19.

Between 19 and 26 is the area between z=-(2/9) and z=(5/9)  or 0.2987 or 0.299

from the z-values, one can go to 2ndVARS 2 (normalcdf) and put in the left sided z-value and then the right sided z-value, separated by a comma, then ENTER