Can someone me with these questions? i’m desperate! as always, i will give brainliest . i promise.

Can some one me with these questions

The pyramid below was dissected by a horizontal plane which shape describes the pyramid horizontal cross section

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.