1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Serga [27]
3 years ago
9

Consider a multiple-choice question exam consisting of 20 questions. Assume that each question has four possible choices, and on

ly one of them is correct. If a student is going to guess solutions at the exam, what is the probability that he answers at most three of them are correct
Mathematics
1 answer:
elena-s [515]3 years ago
8 0

Answer:

0.22514

Step-by-step explanation:

Given :

1 answer from 4 options

p = 1/4 = 0.25 ; q = 1 - 0.25 = 0.75

n = 20

P(x ≤ 3) = p(x =0) +p(x=1) + p(x=2) +p(x=3)

P(x = x) = nCr * p^x * q^(n-r)

p(x =0) = 20C0 * 0.25^0 * 0.75^20 = 0.00317

p(x =1) = 20C1 * 0.25^1 * 0.75^19 = 0.02114

p(x =2) = 20C2 * 0.25^2 * 0.75^18 = 0.06694

p(x =3) = 20C3 * 0.25^3 * 0.75^17 = 0.13389

P(x ≤ 3) = 0.00317+0.02114+0.06694+0.13389 = 0.22514

You might be interested in
Help and Explain please
Rudiy27
The answer is B. Just multiply all of them then divide
4 0
3 years ago
Read 2 more answers
If angle X is an acute angle with tan X = 8/7, what is the value of sec X?
iren [92.7K]

Answer: \frac{\sqrt{113}}{7}

Step-by-step explanation:

As X is an acute angle, all 6 trigonometric functions with an argument of X are positive.

Using the identity 1+\tan^{2} X=\sec^{2} X,

1+\left(\frac{8}{7} \right)^{2}=\sec^{2} X\\\\\sec^{2} X=\frac{113}{49}\\\\\therefore \sec X=\boxed{\frac{\sqrt{113}}{7}}

5 0
1 year ago
Which expression is the simplest form of -(2x + y) + 3(x - 4y)?
xenn [34]

Answer:

The answer is x - 13y

Step-by-step explanation:

6 0
3 years ago
given XZ with X(-4 3) and Z(6 ,-2) find the coordinates of y if y divides XZ one-fifth of the way from X to Z
Dvinal [7]

Answer:

Step-by-step explanation:...

6 0
3 years ago
Solve the inequality 2{4+2x] is less than 5x+5
djyliett [7]

Answer:

kxixidididddiidididficuc

5 0
3 years ago
Other questions:
  • I need help on this plzzz
    7·2 answers
  • Find the value of the expression. pm + 4 for m = 4 and p = 4
    15·2 answers
  • Infinite Algebra 2
    15·1 answer
  • PLS I need help with this,
    12·1 answer
  • A boat is moving due east at 15 miles per hour when it encounters a current LaTeX: \textbf{C} = 2\textbf{i}+17\textbf{j}C = 2 i
    6·1 answer
  • Can someone help me out --x-3>-1
    11·1 answer
  • [(b+3)÷(a–2)](−4) if a=−5, b=6
    14·1 answer
  • HURRY I'LL PICK A BRAINLIEST PERSON!!!
    11·2 answers
  • Help with this question plzz
    6·1 answer
  • Find the product -1.2(0.04)
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!