A scientist for a company that manufactures processed food wants to assess the percentage of fat in the company's bottled sauce. The advertised percentage is 15%. The scientist measures the percentage of fat in 20 random samples. Previous measurements found that the population standard deviation is 2.6%.
As part of the initial investigation, the scientist creates a probability plot to check for normality and to evaluate the distribution.
Choose Graphs > Probability Plot > Single Y Variable: Simple.
In Y variable, enter Percent Fat.
Interpret the results
The data points are relatively close to the fitted normal distribution line. The p-value is greater than the significance level of 0.05. Therefore, the scientist fails to reject the null hypothesis that the data follow a normal distribution.