Kenley has 100 songs on her digital music player. of the songs, seventeen hundredths are country songs, two tenths are musicals, and four tenths are classical music songs. what part of the songs are either country or musical?

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.