Determine the probability that a randomly selected person had a birthday on the 1st day of the month

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.

Ithink i know it but i want to be sure so can you me out ?

Me asap the graph shows the relationship between the price of frozen yogurt and the number of ounces of frozen yogurt sold at different stores and restaurants according to the line of best fit about how many ounces of frozen yogurt can someone purchase for $5? 1 cost of frozen yogurt 1.5 2 13 15.5 cost (5) no 2 4 6 8 10 12 14 16 18 20 size (oz)