The grades on the last history exam had a mean of 80%. assume the population of grades on history exams is known to be distributed normally, with a standard deviation of 5%. approximately what percent of students earn a score between 70% and 80%?

a. 2.2%
b. 10%
c. 47.7%
d. 50%
e. 52.5%

What are the solutions of the equation? z^2 + 11z + 24 = 0 a. 8, -3 b. 8, 3 c. -8, -3 d. -8, 3

Is the response to the survey question "did you smoke in the last week question mark "response to the survey question "did you smoke in the last week? " a discrete random variable, a continuous random variable, or not a random variable?

Abank manager wants to encourage new customers to open accounts with principals of at least $2,500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?