Indicate which of the following is a correlational design and the correlation coefficient to compute.
(a) We measure participants’ age and their daily cell phone usage.
(b) We separate participants into three age groups, and then observe their cell phone usage during a one hour period.
(c) A teacher uses students’ grades on their first exam to predict their final exam grades.
(d) We ask whether a website rated as most attractive has more visitors than one rated as second most attractive, and so on, for the top ten websites.
(e) We compare performance on an attention test of people who were and were not given an energy drink.