You have a jar of pennies and quarters. You want to choose 15 coins that are worth exactly $1.35,
a. Write and solve a system of equations that models the situation,
b. In your solution reasonable in terms of the original problem? Explain.

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