How can you show your work on rounding

43lbs of tomatos cost $387. how much would 41lbs cost

Write the equation in logarithmic form e^x=403.429

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”?