Determine if the equation x2 – y = 1 defines y as a function of x. no. at least one input results in two outputs. no. at least one output results in two inputs. yes. one output results in one input. yes. one input results in one output.

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.