Answer:
86%
Step-by-step explanation:
Let g represent the mean mark for the 10 girls in the class. Then the mean mark for the class was ...
10g +20(62%) = 30(70%)
g = 3(.7) -2(.62) . . . . . . . . . divide by 10 and subtract 2(.62)
g = .86 = 86%
The mean mark for girls was 86%.
_____
You can do this in your head if you consider it in terms of deviations from the mean. The second equation above can be rewritten and factored as ...
g = 70% +2(70% -62%)
That is, because there are 2 boys for every girl, the girl's score is above the mean by an amount that is 2 times the amount that the boy's score is below the mean. The boys' score is below by 8%, so the girls' score is above by 16%, so is 86%.
Answer:
)Alex picks more red cards than black cards,
Step-by-step explanation:
Answer:
m<1 = 51
m<2 = 61
m<3 = 29
Step-by-step explanation:
three angles of a triangle = 180
so knowing that add 68 + 61 to get 129
now subtract cause the last angle will = 180-129 = 51
for angle two is 61 cause their congruent
now we have one angle = 90 and another 61
add them 90+61= 151
now subtract 180-151 = 29
Answer:
3/4 * 2/5
Step-by-step explanation:
Areas is L * W
(1/5 + 1/5) * (1/4 + 1/4 + 1/4) = 2/5 * 3/4
Answer:
Step-by-step explanation:
probability= <u>no of possible outcom</u><u>e</u>
total outcome
therefore p(1)=
N. B, a dice has 6faces so 2dice has 12 faces