Question

$df$= ________

Short answer

The degrees of freedom $df=24$

Step-by-step solution

Given information

Given in the question that, Suppose an airline claims that its flights are consistently on time with an average delay of at most $15$minutes. It claims that the average delay is so consistent that the variance is no more than $150$ minutes. Doubting the consistency part of the claim, a disgruntled traveler calculates the delays for his next $25$ flights. The average delay for those $25$ flights is$22$ minutes with a standard deviation of $15$minutes.

Explanation

The degrees of freedom can be calculated as shown below:

$n-1=25-1$

$=24$