Aprofessor must randomly select 4 students to participate in a mock debate. there are 18 students in his class. in how many different ways can these students be selected, if the order of selection does not matter?

a. 3,060
b. 38,390
c. 73,440
d. 1,768

Atriangle has an area of 72 square inches. if the base of the triangle has a length of 18 inches, what is the height of the triangle? use the formula for the area of a triangle: area = (base)(height) type a numerical answer in the space provided. do not include the units or spaces in your answer.

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

(b) suppose that consolidated power decides to use a level of significance of α = .05, and suppose a random sample of 100 temperature readings is obtained. if the sample mean of the 100 temperature readings is x⎯⎯ = 60.990, test h0 versus ha and determine whether the power plant should be shut down and the cooling system repaired. perform the hypothesis test by using a critical value and a p-value. assume σ = 5. (round your z to 2 decimal places and p-value to 4 decimal places.)