Mathematics

Pretty Lady

21 March, 02:52

A study was conducted at the University of Waterloo on the impact characteristics of football helmets used in competitive highschool programs. There were three types of helmets considered, classified according to liner type: suspension, padded-suspension, and padded. In the study, a measurement called the Gadd Severity Index (GSI) was obtained on each helmet using a standardized impact test. A helmet was deemed to have failed if the GSI was greater than 1200. Of the 81 helmets tested 33 failed the GSI 1200 criterion. If the test was to be conducted again, how many suspension-type helmets should be tested so that the margin of error does not exceed 0.05 with 95% confidence?

A) 385

B) 372

C) 271

D) 250

E) 82