The Program for International Student Assessment (PISA) conducts test in mathematics in countries throughout the world. For 15-yer-olds in all developed countries, the scores in 2012 were normally distributed with a mean of 494 and a standard deviation of 92. If there were 5,000 students who took the test, how many scored between 310 and 494?

a
2492.5
b
47.5
c
2375
d
49.85

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?

If 7x=9y, y/z = 7/5 , then x/z = (a) 2/7 (b) 7/9 (c) 9/5 (d) 9/7 (e) 5/9

Alice is paying her bill at a restaurant. but tax on the cost of a male is 5%. she decides to leave a tip 20% of the cost of the meal plus the tax