Biking at 10 mph, it takes Kristen hour to reach the train station to go to work. Kristen then takes the train to work, and it takes another hour for her to get to work when the train travels 20 mph. How far does Kristen travel to work?

The number of chocolate chips in an 18-ounce bag of chocolate chip cookies is approximately normally distributed with a mean of 1252 chips and standard deviation 129 chips. (a) what is the probability that a randomly selected bag contains between 1100 and 1500 chocolate chips, inclusive? (b) what is the probability that a randomly selected bag contains fewer than 1125 chocolate chips? (c) what proportion of bags contains more than 1225 chocolate chips? (d) what is the percentile rank of a bag that contains 1425 chocolate chips?

Tell whether the two rates form a proportion

At your job you're paid $50 per week plus $3 per sale at least how many saled do you need to make in order to have over $250