A researcher wants to carry out a hypothesis test involving the mean for a sample of size n= 18. She does not know the true value of the population standard deviation but is reasonably sure that the underlying population is approximately normally distributed. Should she use a z-- test or a t-- test in carrying out the analysis? Why?

Explain how you can use the associative property to evaluate (7x50)x4.

Acylinder with a base diameter of x units has a volume of jxcubic units which statements about the cylinder are true? check all that apply. the radius of the cylinder is 2 x units. the radius of the cylinder is 2x units. the area of the cylinder's base is 200 square units. the area of the cylinder's base is a square units. the height of the cylinder is 2x units. the height of the cylinder is 4x units. mark this and return save and exit next submit

Is the figure congruent? yes or no?