When multiplying and/or dividing fractions, answer if each of the statements below are TRUE or FALSE. 1: The denominators MUST be the same.

2: You must convert mixed numbers into improper fractions before multiplying or dividing.

3: You can keep mixed numbers when performing multiplication or division.

4: Numerators must be multiplied by numerators and denominators must be multiplied by denominators.

1. Only true to division. Most likely though when multiplying it's more helpful to have the denominators the same.

2. True

3. False

4. True

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.

irst, find the z score of a score of 80. this is given by the formula z = (x-u)/o, where x is the score, u is the mean, and o is the standard deviation. this gives

z = (80-78)/12 = 1/6 = .1667

now, find what percentile a z score of 1/6 correlates to in the normal distribution.

a z score of 1/6 = .1667 is equivalent to the 56.36th percentile of the distribution. so the probability a score is over this is 1-.5636 = .4364

the mean of a sample mean is equal to the original mean. however, the standard deviation of a sample mean is equal to the original standard deviation divided by the square root of n (sample size). so the new standard deviation is 12/sqrt(16) = 3.

the new z score is 80-78/3 = 2/3 = .667. this is equivalent to the 74.86th percentile. so the probability that the mean will be greater than this score is 1-.7486 = .2514.