http://prntscr.com/6bwlje

Question

igreen · Answer

Set up a proportion:

$\dfrac{80}{500} = \dfrac{x}{25}$

igreen · Answer

Multiply 25 to both sides:

$x = \dfrac{80 \times 25}{500}$

Simplify that

ribhu · Answer

probably 4 should be the answer from @iGreen calculations

ribhu · Answer

the explanation is that probability of choosing one green marble from the whole lot

igreen · Answer

@ribhu Let her do the calculations.

ribhu · Answer

then this probability can be multiplied with the required sample size.

ribhu · Answer

@iGreen u didn't explain anything and just wrote the expression, this approach never helps. that was nothing but similar as giving direct answers. not calculations concept is important

linn99123 · Answer

OK THANKZ I GOT IT I DID GOT 4

igreen · Answer

@ribhu It does help..you giving out the answer is giving direct answers..this is not..the asker is participating..