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
ss7ja [257]
3 years ago
10

A multiple-choice standard test contains total of 25 questions, each with four answers. Assume that a student just guesses on ea

ch question and all questions are answered independently. (a) What is the probability that the student answers more than 20 questions correctly? (b) What is the probability that the student answers fewer than 5 questions correctly?
Mathematics
1 answer:
weqwewe [10]3 years ago
7 0

Answer:

a)  8*88*10⁻⁶ ( 0.00088 %)

b) 0.2137 (21.37%)

Step-by-step explanation:

if the test contains 25 questions and each questions is independent of the others, then the random variable X= answer "x" questions correctly , has a binomial probability distribution. Then

P(X=x)= n!/((n-x)!*x!)*p^x*(1-p)^(n-x)

where

n= total number of questions= 25

p= probability of getting a question right = 1/4

then

a) P(x=n) = p^n = (1/4)²⁵ = 8*88*10⁻⁶ ( 0.00088 %)

b) P(x<5)= F(5)

where F(x) is the cumulative binomial probability distribution- Then from tables

P(x<5)= F(5)= 0.2137 (21.37%)

You might be interested in
Marco has a bag of 50 colored marbles.there are 12 blue marbles,18 black marbles,and 20 red marbles.what is the ratio of the num
iren2701 [21]

The answer is 2:3 because it is 12:18 simplified.

8 0
2 years ago
One evening, it snowed in several towns. The number of inches of snow the towns received are shown in the list below.
Rama09 [41]

Answer:

3/4,3/4,3/4,3/4,1,1,2,11/2,11/2,11/4,11/4

Step-by-step explanation:

we just arrange the number from the smallest to bigger

8 0
2 years ago
A can of paint is a right circular cylinder. The radius of the base is 5 centimeters and the height is 12 centimeters. Find the
seropon [69]
I’ve already tried to answer this question but somebody already said it was wrong I’m sorry baby
5 0
3 years ago
Read 2 more answers
PLEASE HELP
Sergeeva-Olga [200]

Answer:

y = 2

Step-by-step explanation:

I will solve this problem, using the elimination method.

-2(5x - 3y) = -11

-10x + 6y = 22

2x - 6y = -14

Subtract and divide for x

-8x = 8

x = -1

Input -1 into the equations

2(-1) - 6y = -14

-6y - 2 = -14

-6y = -12

y = 2

Thanks!

5 0
3 years ago
You choose a tile at random from a bag containing 4 A’s, 3 B’s, and 5 C’s. You replace the first tile in the bad and then choose
shtirl [24]

Answer:

P(B and B) = 1/9

Step-by-step explanation:

There are 4+3+5 = 12 tiles in total

The probability of selecting a B would be 4/12=1/3

When you are replacing a B tile, planning to pick a B tile again, the total tile count doesn't change. Therefore, because the two events are independent, their probabilities are multiplied and so P(B and B) = P(B) * P(B) = 1/3 * 1/3 = 1/9

3 0
3 years ago
Other questions:
  • Simplify 3sqrt -32 x^4 y^6
    14·1 answer
  • HELP PLEASE! Find the standard deviation for Data set 1 and 2. round to the nearest hundred. DATA SET ONE: 8.2, 11.6 8.7, 10.6,
    6·1 answer
  • Use the substitution method to solve the system of equations. Choose the correct ordered pair.
    9·2 answers
  • Help me pleaseeeeeeeeeeeeeeeee
    9·1 answer
  • What is the greatest value of 3x+8
    13·1 answer
  • A grocer has two kinds of candies: one sells for 90 cents per pound and the other sells for 40 cents per pound. How many pounds
    7·1 answer
  • In ΔFGH, the measure of ∠H=90°, FH = 39, GF = 89, and HG = 80. What ratio represents the cotangent of ∠G?
    9·1 answer
  • 1. 6x - 29 = 115<br> 2. 3y - 1 = 29<br> 3. 4z - 32 = 36<br><br> find x, y, and z
    10·1 answer
  • Please answer this (who ever answers correctly gets brainlest)
    13·1 answer
  • Given the situation, which inequality models the number of additional weeks marie needs to continue saving to afford the home re
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!