The information above is shown in the normal distribution curve shown below
Step 1 : Find the z-score for 5 hours
rounded to 2 dp
Step 2: Read the value of z-score on the z-table
As shown in the second picture, the value z at -1.18 is 0.1190
Step 3: The proportion can be written in percentage form which is 11.90% rounded to 12% to nearest whole number
Step 1 : Find the z-score for 5 hours
Step 2: Read the value of z-score on the z-table
As shown in the second picture, the value z at -1.18 is 0.1190
Step 3: The proportion can be written in percentage form which is 11.90% rounded to 12% to nearest whole number