Aspectrophotometer used for measuring co concentration [ppm (parts per million) by volume] is checked for accuracy by taking readings on a manufactured gas (called span gas) in which the co concentration is very precisely controlled at 70 ppm. if the readings suggest that the spectrophotometer is not working properly, it will have to be recalibrated. assume that if it is properly calibrated, measured concentration for span gas samples is normally distributed. on the basis of the six readings—69, 68, 82, 85, 77, and 72—is recalibration necessary? carry out a test of the relevant hypotheses using α = 0.05.

To determine the number of deer in a forest a forest ranger tags 280 and releases them back

Quick! a survey of 57 customers was taken at a bookstore regarding the types of books purchased. the survey found that 33 customers purchased mysteries, 25 purchased science fiction, 18 purchased romance novels, 12 purchased mysteries and science fiction, 9 purchased mysteries and romance novels, 6 purchased science fiction and romance novels, and 2 purchased all three types of books. a) how many of the customers surveyed purchased only mysteries? b) how many purchased mysteries and science fiction, but not romance novels? c) how many purchased mysteries or science fiction? d) how many purchased mysteries or science fiction, but not romance novels? e) how many purchased exactly two types of books?

A. s.a.! similarity in right triangles, refer to the figure to complete this proportionc/a = a/? a.) cb.) hc.) rd.) s