stuck on maths question! (1 Viewer)

[almu]

Hi guys!

I've got this stupid maths question ive been trying to workout for the past half hour, any help is appreciated!

Here it is:

Suppose there are two light bulb maufacturing compaines, company A and Company B. Company A produces high quality light bulbs and company B produces poorer quality light bulbs.
A sample of 2000 light bulbs from each company were tested. The test involves measuring the number of hours the light bulbs lasted. Of the 2000 light bulbs from company A, 100 died before 800 hours. For Company B, 320 died before 800 hours.
Suppose light bulb retailers deal exclusively with one company. A certain retailer, Big Henry's light bulbs sold 320 light bulbs to an electrical company. The electrical company installed the light bulbs in 24-hour retail stores. After 800 hours, 51 of the installed light bulbs had blown.
Which light bulb maufacturing company does Big Henry's light bulb deal with? Explain and justify you answer.

 

[PC]

Interesting question. These usually lead into mean and standard deviation type questions ...

From the data:
Company A: 100÷2000 = 5% blow before 800 hours
Company B: 320÷2000 = 16% blow before 800 hours

From Big Henry's:
Rate = 51 ÷ 320 = 15.9% blow before 800 hours

From this information, it appears that Big Henry gets his bulb from Company B.