A professor at a university wants to estimate the average number of hours of sleep the students get during exam week. The professor wants to find a sample mean that is within 4.266 hours of the true average for all college students at the university with 99% conconfidence. If the professor knows the standard deviation of the sleep times for all college students is 2.539, what sample size will need to be taken

The sample size is

Step-by-step explanation:

From the question we are told that

   The margin of error is  E =4.266

    The standard deviation is  

From the question we are told the confidence level is  99% , hence the level of significance is    

=>  

Generally from the normal distribution table the critical value  of   is  

Generally the sample size is mathematically represented as  

=>  

=>  

14

step-by-step explanation:

14 x 3 = 42

a reflection across the x-axis , followed by the by a reflection across the y-axis , and then a scale dilation of 0.5 .