12.18 What kinds of activities do you engage in when using a device while viewing video content on a TV screen? An IAB and MARU Matchbox study captured multitasking activities of adults who use different devices while watching TV. The study reported that 320 of 444 (72%) smartphone users sampled, 194 of 347 (56%) of computer users sampled, and 141 of 261 (54%) of tablet users sampled used their device to check social media unrelated to the video while watching TV. a. Is there evidence of a significant difference among the smartphone, computer, and tablet users with respect to the proportion who use their device to check social media unrelated to the video while watching TV? (Use a =0.05.) b. Determine the p-value and interpret its meaning. c. If appropriate, use the Marascuilo procedure and a = 0.05 to determine which groups differ.