Answer:
31.25% probability that the Blair family had at least 3 girls
Step-by-step explanation:
For each children, there are only two possible outcomes. Either it was a girl, or it was not. The probability of a child being a girl is independent of any other children. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
They had 4 children.
This means that 
The probability of a child being a girl is 0.5
This means that 
Probability of at least 3 children:





31.25% probability that the Blair family had at least 3 girls
Answer:
y = 3/5x + 5
Step-by-step explanation:
Slope-intercept form is y = mx + b where m is the slope (rise / run of the line) and b is y-intercept (y value of where the line intersects with the y-axis.
The line is rising up 3 and run to the right 5 and so it's slope is 3/5. The line intersects with the y-axis at a y value of 5 and so it's y-intercept is 5.
Therefore, your answer in slope-intercept form is y = 3/5x + 5.
Answer:
y = 18
Step-by-step explanation:
71 - 5 = 4y - 6
66 = 4y - 6
72 = 4y
18 = y
P.S. I am not 100% sure if this is correct if it isn't I am greatly sorry