The test grades at a large school have an approximately normal distribution with a mean of 50 and a standard deviation of 5 points. What is the score that cuts off the top 10% of the scores? It would be greatly appreciated if someone could also explain how they got to the answer, so I'll understand in the future. <3

What is the slope of a line that is perpendicular to y = 3x + 1

What is the vertex form of f(x) = x2 + 6x + 3

1- is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis. 2- 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. 3- 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 part b?