Plz & explain what set of reflections would carry triangle abc onto itself? a.) x-axis, y=x, y-axis, x-axis b.) x-axis, y-axis, x-axis c.) y=x, x-axis, x-axis d.) y-axis, x-axis, y-axis, x-axis

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.