we know that
The probability that "at least one" is the probability of exactly one, exactly 2, exactly 3, 4 and 5 contain salmonella.
The easiest way to solve this is to recognise that "at least one" is ALL 100% of the possibilities EXCEPT that none have salmonella.
If the probability that any one egg has 1/6 chance of salmonella
then
the probability that any one egg will not have salmonella = 5/6.
Therefore
for all 5 to not have salmonella
= (5/6)^5 = 3125 / 7776
= 0.401877 = 0.40 to 2 decimal places
REMEMBER this is the probability that NONE have salmonella
Therefore
the probability that at least one does = 1 - 0.40
= 0.60
the answer is
0.60 or 60%
The sample % of these two populations would be 100/size (of student body at each school) x 100 so this would compare the two student bodies preferences for the particular type of candy bar. However, the actual % of the whole student body at each school would be a factor also. If the high school only had 200 students then this would be 50% representative but if the middle school had say 500 students this would only be 20% representative so this would have to be taken into account too. It might be more representative to have the same % of the student bodies respectively for the sample.
IF USING GEOMETRY...
x-axis = (x, -y)
Because the x does not have a negative sign the number DOES NOT change to its opposite form, but because the y has a negative sign the number DOES changes to its opposite form (from negative number to positive.)
So... if we use the formula of x-axis, which is (x, -y), the coordinates (-7,-3) would change to (-7, 3)
ANSWER (-7, 3)