A company manufactures tennis balls. When its tennis balls are dropped onto a concrete surface from a height of inches, the company wants the mean height the balls bounce upward to be inches. This average is maintained by periodically testing random samples of tennis balls. If the t-value falls between and  , then the company will be satisfied that it is manufacturing acceptable tennis balls. A sample of balls is randomly selected and tested. The mean bounce height of the sample is inches and the standard deviation is inch. Assume the bounce heights are approximately normally distributed. Is the company making acceptable tennis balls? Find and . nothing nothing