To find the area under the normal distribution between z = -0.30 and z = 0.90, you can use a standard normal distribution table or a calculator with a normal distribution function.
Using a standard normal distribution table:
Look up the area to the left of z = 0.90 in the standard normal distribution table. This will give you a value of 0.8159.
Look up the area to the left of z = -0.30 in the standard normal distribution table. This will give you a value of 0.3821.
Subtract the value from Step 2 from the value from Step 1 to find the area between z = -0.30 and z = 0.90:
Area = 0.8159 - 0.3821 = 0.4338
Using a calculator with a normal distribution function:
Use the normal distribution function on your calculator with a mean of 0 and a standard deviation of 1 to find the area to the left of z = 0.90. This will give you a value of 0.8159.
Use the normal distribution function on your calculator with a mean of 0 and a standard deviation of 1 to find the area to the left of z = -0.30. This will give you a value of 0.3821.
Subtract the value from Step 2 from the value from Step 1 to find the area between z = -0.30 and z = 0.90:
Area = 0.8159 - 0.3821 = 0.4338
Therefore, the area under the normal distribution between z = -0.30 and z = 0.90 is 0.4338.