## PELIN'S MATHEMATICS PAGE

ONLINE QUIZ ABOUT GAUSSIAN DISTRIBUTION

TEST YOURSELF!

Choose the correct answer. You will have a chance to see if your answer is correct or not after choosing the answer. If you want to see the solutions please click here:

Solutions of questions

1.     X is a normally distributed variable with mean = 30 and standard deviation  = 4. Find P(x < 40).

0.9938
0.9966
0.9945

2.     A radar unit is used to measure speeds of cars on a motorway. The speeds are normally distributed with a mean of 90 km/hr and a standard deviation of 10 km/hr. What is the probability that a car picked at random is travelling at more than 100 km/hr?

0.1787>
0.1587
0.1566>

3.     For a certain type of computers, the length of time between charges of the battery is normally distributed with a mean of 50 hours and a standard deviation of 15 hours. John owns one of these computers and wants to know the probability that the length of time will be between 50 and 70 hours.

0.4088
0.4055
0.4082

4.     A large group of students take a test in Physics and the final grades have a mean of 70 and a standard deviation of 10. If we can approximate the distribution of these grades by a normal distribution what percent of the students should pass the test (grades 60)?

%86.78
%85.66
%84.13