Answer:
0.59% probability that exactly 97 out of 100 randomly sampled American adults had chickenpox during childhood.
Step-by-step explanation:
For each person, there are only two possible outcomes. Either they have had chickenpox, or they have not. The probability of a person having had chickenpox is independent from other people. So we use the binomial probability distribution to solve this problem.
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.
90% of Americans have had chickenpox by the time they reach adulthood.
This means that 
Suppose we take a random sample of 100 American adults. Is the use of the binomial distribution appropriate for calculating the probability that exactly 97 out of 100 randomly sampled American adults had chickenpox during childhood
This is
when
. So


0.59% probability that exactly 97 out of 100 randomly sampled American adults had chickenpox during childhood.
Answer:
x=63/8
Step-by-step explanation:
9/8=x/7
or, 9*7=x*8
or, 63=8x
x=63/8
Answer:
He saw <u>1 duck</u> and <u>3 dogs</u>.
Step-by-step explanation:
Given:
Evan went to the park and saw four animals.
Each animal was either a duck or a dog.
He saw a total of 14 legs.
Now, to find the number of each animal he had seen.
Let the number of duck be 
And the number of dog be 
So, total number of animals:

Now, the total number of legs he did see:
<em>As we know the legs of a duck are 2 and a dog are 4.</em>
Adding both sides by -16 we get:

Dividing both sides by -2 we get:

The number of duck = 1.
Now, putting the value of
in above equation we get:


The number of dogs = 3.
Therefore, he saw 1 duck and 3 dogs.
Answer:
y = -5
Step-by-step explanation:
yeah-ya....... right?