What is the value of 13x^-3y^-1 for x=-1 and y=4 hel so stressed need this 13x^-3y^-1 for x=-1 and y=4 a) -13/4 b) -52 c) -4/13 d) -156

Ur environment is very sensitive to the amount of ozone in the upper atmosphere. the level of ozone normally found is 4.04.0 parts/million (ppm). a researcher believes that the current ozone level is not at a normal level. the mean of 2525 samples is 4.44.4 ppm with a standard deviation of 0.80.8. assume the population is normally distributed. a level of significance of 0.020.02 will be used. make the decision to reject or fail to reject the null hypothesis. answer tables

Huong is organizing paperback and hardback books for her club's used book sale. the number of paperbacks is 12 less than three times the number of hardbacks. huong had 162 paperbacks. how many hardback books were there?

Atriangle has side lengths of x, x+11, and 3x+5. what is the perimeter? a. 3x^2 + 38x + 55 b. 4x + 16 c. 5x + 16 d. 3x^3 + 38x^2 + 55x