One-third of a number is 7. Find the number.

Julia chooses a card at random from her set of cards. what is the probability that the card is labeled cat or hamster?

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

Why does the shape of the distribution of the weights of russet potatoes tend to be symmetrical?