Question 4 (5 marks) The probability distribution table shows the probabilities of having 0, 1, 2 or 3 girls in a family
with 3 children.
1 2 3
3a3aa
P(X - x)
a Find the value for a.
[2]
121
b Find the expected value for the number of girls in a family with 3 children.
In a sample of 400 children, find the expected number of families that have 2 girls.

answer: i don't understand. what are the options

step-by-step explanation:

1/3

step-by-step explanation:

to find this, you can divide 12 by 4 which is 3 or you can multiply 4 until you reach 12 (4x3=12). both should give you 3, meaning theres three times less bananas than there are oranges.

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.