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:
voce n colocou as latas
Step-by-step explanation:
nao da para saber
descupa
Step-by-step explanation:

15y + 31 = 61
15y = 61 - 31
15y = 30
y = 30 ÷ 15
<u>y = 2</u>
Answer:
0.5
Step-by-step explanation:
The given ordered pairs are: (1,2) (2,2.5) (3,3) (4,3.5) (5,4)
The corresponding sequence is :
2,2.5,3,3.5, 4,....
We can see that there is a common difference of d=0.5.
Better still we could use the slope formula:

We substitute the point (1,2) and (2,2.5).
The rate of change of this sequence is:
