A company installs new central-heating furnaces and has found that for 23% of all installations. a return visit is needed to make some modications. Six installations were made in a particular week. Assume independence of outcomes for these installations. Complete parts a. through 0. below. E) a. What is the probability that a return visit will be needed in all these cases? 0.000148 (Round to six decimal places as needed.) b. What is the probability that a retum visit will be needed in none of these cases? :| (Round to six decimal places as needed.)