Question 1203242
population mean is 153 seconds.
population standard deviation is 35 seconds.
sample size is 23.
standard error = 35 / sqrt(23) = 7.298.
probability that the sample will have a mean length of less than 149.35 seconds is equal to .3085 = 30.85%.


keep in mind that you may need to round to the nearest percent.
i didn't do that.
this applies to all the problemms you posted that i answered.


here are the results, using the same calculator i used for all 3 problems.


<img src = "http://theo.x10hosting.com/2023/081104.jpg">