i need help on this math problem>>> really hard?

Question

To preidct his income, Mr. Green detrmines the portions of his crop free of deseases one motnh prior to harvest. He samples75 ears of cornfrom a field and detrmines that 5 of them are diseased. From a deffernet part of the feild, a sample of 90 ears has 8 diesed ears of corn. Mr. Green estimates that he will harves 42000 ears of corn. Determine a reasonable mathematical estimate for the numbers of diesed ears in the harvest.

thanks for the help

Answer 1

There would be about 3263.4 diseased ears of corn.
First, you find the percent of disease out of the 75 ears(6.66%)...then you find the percent of disease out of 90 ears(8.88%). Then you average the percents together by adding them uo and dividing by two (6.66+8.88=15.54/2=7.77) Then you set up this equation.

is %
-- = --
of 100

( 'is' over 'of' equals '%' over 100)
"is" is the part you are trying to figure out
"of" is the whole part which is 42000
"%" is 7.77%
100 is just the standard number that is always used.

So once you set up that equation and fill in the numbers, you multiply 7.77*42000 which equals 326340, then you divide that by 100 which gives you 3263.4 ears of infected corn.

Answer 2

Diseased ones: 1/2 * (5/75+8/90) = 7/90

T=42000

Td = 42000*7/90 = 9800/3 ~ 3267

Answer 3

ok so 75/5=15 1/15 of the ears of corn are not healthy in thew first example
and 90/8=11.25 so 4/45 of the ears of the corn are not healthy in the second example.
if we average them we get 7/90 which is how many he will most probably loose to disease.
then all we have to do is divide 42,000 by 90 which is 466.6 recuring and then times this by 7 which is 3266.2 recuring and thats your answer

Answer 4

10

Answer 5

in his first sample 5 / 75 ears of corn are diseased or 6.66666% and in the second sample 8 / 90 ears of corn are diseased or 8.88888%.

the average of the two would be 7.777777%. so 7.77777% of 42000 ears of corn would be

.0777777 * 42000 = 3266.666 or 3267 ears of corn

Answer 6

I think that 3,360 ears would be diseased out of 42,000.