If a piece of paper is chosen at random, what is the probability that it will be a vowel?

Can someone me do math because i am having a breakdown rn because i don’t get it

For the inequality |c| < |d| to be true, which of the following must be true?

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.