# Normal distribution calculator

Enter mean (average), standard deviation, cutoff points, and this normal distribution calculator will calculate the area (=probability) under the normal distribution curve.## Normal distribution practice problems:

- Normal distribution GPA

The average GPA is 2.78 with a standard deviation of 4.5. What are students in the bottom the 20% having what GPA? - Life expectancy

The life expectancy of batteries has a normal distribution with a mean of 350 minutes and standard deviation of 10 minutes. What the range in minutes 68% of the batteries will last? What is the range in minutes approximately 99.7% of batteries will last? - Assembly time

The assembly time for the toy follows a normal distribution with a mean of 75 minutes and a standard deviation of 9 minutes. The company closes at 5 pm every day. If one starts assembling at 4 pm what is the probability that he will finish before the comp - Performance comparing

A standardized test was administered to thousands of students with a mean score of 85 and a standard deviation of 8. A random sample of 50 students were given the same test and showed an average score of 83.20. Is there evidence to show that this group ha - SD - mean

The mean is 10 and the standard deviation is 3.5. If the data set contains 40 data values, approximately how many of the data values will fall within the range of 6.5 to 13.5? - Decides

Decide by calculation how many candidates out of a total of 1000 candidates for the position of CEO meet the eligibility requirements for the desired performance of this top management position with at least 67% probability - provided, of course, that the - 10km race

Joan's finishing time for the bolder boulder 10 km race was 1.77 standard deviations faster than the women for her age group. There were 415 women who ran in her age group. Assuming a normal distribution, how many women ran faster than Joan? - Lifespan

The lifetime of a light bulb is a random variable with a normal distribution of x = 300 hours, σ = 35 hours. a) What is the probability that a randomly selected light bulb will have a lifespan of more than 320 hours? b) Up to what value of L hours can the - Statistical survey

Write TRUE OR FALSE for each question: 1 Standard deviation is a measure of central location. 2. The most frequent observation in a data set is known as the mode. 3 The most passive method of data collection is observation. 4 Access time for secondary dat - An exam - normal distribution

5000 students take an exam with a mean of 59 and a deviation of 8. How many students will score less than 75? - A machine

A machine produces steel rods of normally distributed length; the mean length and the standard deviation being 50.0 cm and 0.5 cm respectively. The rods do not conform to safety standards if they are either shorter than 49.1 cm or longer than 50.7 cm in l

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