Using the binomial distribution, it is found that:
The probability that the student will get 15 correct questions in this test by guessing is 0.0207 = 2.07%.
For each question, there are only two possible outcomes, either the guess is correct, or it is not. The guess on a question is independent of any other question, hence, the binomial distribution is used to solve this question.
Binomial probability distribution
The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem:
- There are 20 questions, hence
.
- Each question has 2 options, one of which is correct, hence

The probability is:

In which:







Then:

The probability that the student will get 15 correct questions in this test by guessing is 0.0207 = 2.07%.
You can learn more about the binomial distribution at brainly.com/question/24863377
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Algebra Examples
Popular Problems Algebra Find the Domain and Range y=3/2x^2+4x-9
y
=
3
2
x
2
+
4
x
−
9
The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined.
Interval Notation:
(
−
∞
,
∞
)
Set-Builder Notation:
{
x
|
x
∈
R
}
The range is the set of all valid
y
values. Use the graph to find the range.
Interval Notation:
[
−
35
3
,
∞
)
Set-Builder Notation:
{
y
∣
∣
∣
y
≥
−
35
3
}
Determine the domain and range.
Domain:
(
−
∞
,
∞
)
,
{
x
|
x
∈
R
}
Range:
[
−
35
3
,
∞
)
,
{
y
∣
∣
∣
y
≥
−
35
3
}
image of graph
so wt's the question of this pic?
the circle is 5; the triangle is 2; and the square is 6
20% as a decimal = 0.20 × 69.99=£14.00
69.99-14=55.99
Step-by-step explanation: