A submarine began at sea level and descended toward the ocean floor at a rate of −0.015 km per minute. Its final depth was −0.3675 km. Estimate how long it took the submarine to reach its final depth by rounding the dividend and divisor to the nearest hundredth. Estimate of the quotient:

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”?