If there was an online shopping site was selling about 420 items per second. At this rate, how many items would it sell in 30 minutes

What is the value of r of the geometric series?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

Rewrite the polynomial -9x5 + 36x4 + 189x3 in factored form.