Question 1151876
z for each of these is (x-mean)/sd
for 700, z is -370/311 or -1.19
for 1000, it is -70/311 or -0.23
for 600, it is -470/311 or -1.51
for 1200 it is 130/311 or 0.42
for 1100 it is 30/311 or 0.10

a. z between -1.19 and +0.10 so probability is 0.4228
b. over 1000 is z>-0.23 so probability is 0.5910
c. under 600 is z < -1.51 so probability is 0.0655
d. between 1000 and 1200 is z between -0.23 and +0.42 so probability is 0.2537