A firm needs to find 100 people who regularly purchase orange juice to complete a survey on a new frozen juice. They sampled 500 people & 75 orange juice buyers have been found. Based upon this info - how many additional people in random sample do they need to interview to reach an expected total of 100 people who regularly purchased orange juice?
How would u calculate this?
2006-09-22 07:26:48 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
75/500 = 100/x
75*x = 100*500
x = 50000/75
x = 667
They've already interviewed 500, so if the ratio stays the same, they need to interview an additional 167.
2006-09-22 07:36:10 · answer #1 · answered by Bramblyspam 7 · 0⤊ 0⤋
Well is 75 buyers were found out of 500 people, you could write this as a fraction
75/500
If you assune that you will get a proportionate response from other people surveyed then you can write a proportion
75/500 = 100/x
Where 100 is the desired number and x is unknown.
Now all you have to is solve for x.
Multiply both sides by x gives
75x/500=100x/x and simplify gives
75x/500=100
Multiply both sides by 500 gives
500 * (75x/500) = 500 * 100
Divide both sides by 75 gives
500/75 * (75x/500) = (500 * 100) / 75 and simplify
x = 666 2/3 (you'd need to call that 667th person)
2006-09-22 07:39:36 · answer #2 · answered by Anonymous · 0⤊ 1⤋
so with the first 500 people they found 75% of the people the need (75 out of 100). So they need 25% more. 25% of 500 is 125
2006-09-22 07:40:59 · answer #3 · answered by Kikka 3 · 0⤊ 0⤋
500 Surveyed - 75 orange buyers found
X Surveyed - 100 orange buyers found
500 * 100 = 50000
50000/75 = 666.67
Additional required = 500-666.67 = 166.67 (round off to 167)
2006-09-22 07:38:00 · answer #4 · answered by sensa 4 · 0⤊ 0⤋
100/75(500)=2000/3=670 approximately
2006-09-22 07:34:37 · answer #5 · answered by raj 7 · 0⤊ 0⤋
set the follow (75/500) = (100/x) solve for x
2006-09-22 07:38:22 · answer #6 · answered by db_maverick420 1 · 0⤊ 0⤋