Hello,
We have to use this relation : 
He we have :

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
The graph of the function -3x+5y=-15 is a linear function we can draw it by finding the values of y for every value of x.
<h3>What is a function?</h3>
It is defined as a special type of relationship, and they have a predefined domain and range according to the function every value in the domain is related to exactly one value in the range.
We have a function:
-3x + 5y = -15
The above function shows a linear function we can write it as:
5y = 3x - 15
y = (3x - 15)/5
If x = 0, y = -3
x = 1, y = -2.4
x = 2, y = -1.8
x = -1, y = -3.6
x = -2, y = -4.2
Thus, the graph of the function -3x+5y=-15 is a linear function we can draw it by finding the values of y for every value of x.
Learn more about the function here:
brainly.com/question/5245372
#SPJ1
<h2>
Put x =
I write the sum of 6x and 2x is at least 39 .</h2>
Step-by-step explanation:
We have,,
6x and 2x
To find, the value of x = ?
According to question,
The sum of 6x and 2x is at least 39
∴ 6x + 2x = 39
⇒ 8x = 39
⇒ x = 
∴ The value of x = 
Thus, put x =
I write the sum of 6x and 2x is at least 39 .