Tap a can till tank in 28 hours, while tap b can fill the same tank in 21 hours. if both taps are open together, how long will it take to fill an empty tank?

1. suppose that scores on a knowledge test are normally distributed with a mean of 71 and a standard deviation of 6. a. label the curve: show the mean and the value at each standard deviation: b. if angelica scored a 76 on the test, what is her z-score? (draw her score on the curve above and label) c. what percent of students did angelica score higher than? how can you tell? d. if 185 students took the test, how many students scored higher than angelica?