An automobile is driven on a straight road, and the distance traveled by the automobile after time t=0 is given by a quadratic function s, where s(t) is measured in feet and t is measured in seconds for 0≤t≤12. Of the following, which gives the best estimate of the velocity of the automobile, in feet per second, at time t=8 seconds?

(adapted from m. m. duguid and j. a. goncalo, living large: the powerful overestimate their own height. ) in a study of power and self-image, participants were not told the true purpose of the study; instead, they believed they were participating in a business simulation. researchers randomly assigned participants to a high power(n = 44) or low-power (n = 44) condition. in the high-power condition, participants recalled a time when they had power over others, and in the low-power condition, they recalled a time when others had power over them. participants were asked to adjust the height (in centimeters) of an electronic graphical image (an avatar)of themselves to reflect their personal appearance. results indicated a statistically significant difference in participants’ perceptions of their own height across the two conditions. participants in the high-power condition created taller self-images (mean = 6.0, standard deviation = 1.5) than participants in the low-power condition(mean = 4.0, standard deviation = 1.0). * describe independent variable- describe how researchers measured the independent variable- explain why the researchers can conclude that there is a cause-and-effect relationship between the independent and dependent variables. - explain what statistical significance means in the context of the study.- explain why debriefing would be necessary in the study. -