Movie companies need to predict the gross receipts of individual movies after a movie has debuted. The accompanying results are the first weekend gross, the national gross, and the worldwide gross (in millions of dollars) of six movies. Complete parts (a) through (d) below. a. Compute the covariance between first weekend gross and national gross, first weekend gross and worldwide gross, and national gross and worldwide gross.
b. Compute the coefficient of correlation between first weekend gross and national gross, first weekend gross and worldwide gross, and national gross and worldwide gross.
c. Which is more valuable in expressing the relationship between first weekend gross, national gross, and wordwide gross, the covariance or the coefficient of correlation? Explain.