The American Academy of Pediatrics recommends that parents begin reading to their children soon after birth, and that parents set limits on screen time. A new study The American Academy of Pediatrics recommends that parents begin reading to their children soon after birth, and that parents set limits on screen time. A new study reinforces these recommendations. In the study, 27 four-year-olds were presented with stories in three different formats: audio (sound only), illustrated (sound and pictures), and animated (sound and animation). During the presentations, a magnetic resonance imaging (MRI) machine measured each child’s brain connectivity. The researchers found a “Goldilocks effect,” i which audio was too cold (with low brain connectivity as the children strained to understand) and animation was too hot (with low brain connectivity as the animation did all the work for the children). The highest connectivity (just right!) was found with the illustrated format, which simulates reading a book to a child. reinforces these recommendations. In the study, 27 four-year-olds were presented with stories in three different formats: audio (sound only), illustrated (sound and pictures), and animated (sound and animation). During the presentations, a magnetic resonance imaging (MRI) machine measured each child’s brain connectivity. The researchers found a “Goldilocks effect,” in which audio was too cold (with low brain connectivity as the children strained to understand) and animation was too hot (with low brain connectivity as the animation did all the work for the children). The highest connectivity (just right!) was found with the illustrated format, which simulates reading a book to a child.

(a) What is the explanatory variable? Is it categorical or quantitative?

(b) What is the response variable? Is it categorical or quantitative?

(c) How many cases are there?