# Math Help - True mean

1. ## True mean

Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2-day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 45 randomly chosen fax transmissions during the next year, yielding a sample mean of 11.44 with a standard deviation of 3.15 pages. At the .01 level of significance, is the true mean greater than 10? Explain your decision

2. Originally Posted by sebchase0625
H0: $\mu < 10$
H1: $\mu > 10$
Use t-distribution (why?). What's the critical value for t (df = 44) when $\alpha = 0.01$?
$t = \frac{11.44 - 10}{3.15/\sqrt{45}} = \, ....$ Is this value larger or smaller than the critical value? What does this mean with regards to accepting or rejecting H0?