problem:The Mean Score on Statistics and Probability test of STEM students is 30.The Standard Deviation is 5.If the teacher administers the test to a class of a 40 students.find the probability that the mean of the sample will be between 27 and 31 .Assume the variable is normally distributed. *Compute the value of standard deviation of the sample mean ? step-by-step ,solution plssss I need ur help ,,,, ​