Jessica knows that the adult population gets, on average, eight hours of sleep each night. A hypothesis test can help her see if college students are different from the adult population. Jessica tabulated that her sample of 101 students got an average of 6.9 hours of sleep each night, with a standard deviation of 2.5. Using the data provided and the formula below, what is the t-statistic that Jessica calculates?

Solve the problem.At a track meet, Russell ran the first heat of the 100-yd dash in 14.5 sec, Sergy in 14.8 sec, and Omar in 15.2 sec. In the second heat, they got 14.3 sec, 14.4 sec, and 14.7 sec. Write a 1 x 3 matrix giving the changes in times. If the changes repeat, who will win?

A.
, Omar
B.
[0.2 0.4 0.5], Sergy
C.
[-0.2 -0.4 -0.5], Sergy
D.
[-0.2 -0.4 -0.5], Russell

The graph of f(x) = ax2 + bx + c is given in the figure. Solve the equation 

A. -8 B. 0 C. 8 D. No real solutions

Find an equation of variation for the given situation.y varies jointly as x and z and inversely as the product of w and p, and  when    and 

A. y = 
B. y = 
C. y = 
D. y = 13pwxz

Translate to an equation and solve.  81% of what is 245?

A. 3000 B. 30 C. 200.08 D. 300