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
nadya68 [22]
3 years ago
7

​41% of U.S. adults have very little confidence in newspapers. You randomly select 10 U.S. adults. Find the probability that the

number of U.S. adults who have very little confidence in newspapers is ​ (a) exactly​ five, (b) at least​ six, and​ (c) less than four.
Mathematics
1 answer:
lys-0071 [83]3 years ago
5 0

Answer:

a) 0.2087 = 20.82% probability that the number of U.S. adults who have very little confidence in newspapers is exactly​ five.

b) 0.1834 = 18.34% probability that the number of U.S. adults who have very little confidence in newspapers is at least​ six.

c) 0.3575 = 35.75% probability that the number of U.S. adults who have very little confidence in newspapers is less than four.

Step-by-step explanation:

For each adult, there are only two possible outcomes. Either they have very little confidence in newspapers, or they do not. The answers of each adult are independent, which means that the binomial probability distribution is used 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.

P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}

In which C_{n,x} is the number of different combinations of x objects from a set of n elements, given by the following formula.

C_{n,x} = \frac{n!}{x!(n-x)!}

And p is the probability of X happening.

​41% of U.S. adults have very little confidence in newspapers.

This means that p = 0.41

You randomly select 10 U.S. adults.

This means that n = 10

(a) exactly​ five

This is P(X = 5). So

P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}

P(X = 5) = C_{10,5}.(0.41)^{5}.(0.59)^{5} = 0.2087

0.2087 = 20.82% probability that the number of U.S. adults who have very little confidence in newspapers is exactly​ five.

(b) at least​ six

This is:

P(X \geq 6) = P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10)

P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}

P(X = 6) = C_{10,6}.(0.41)^{6}.(0.59)^{4} = 0.1209

P(X = 7) = C_{10,7}.(0.41)^{7}.(0.59)^{3} = 0.0480

P(X = 8) = C_{10,8}.(0.41)^{8}.(0.59)^{2} = 0.0125

P(X = 9) = C_{10,9}.(0.41)^{9}.(0.59)^{1} = 0.0019

P(X = 10) = C_{10,10}.(0.41)^{10}.(0.59)^{0} = 0.0001

Then

P(X \geq 6) = P(X = 6) + P(X = 7) + P(X = 8) + P(X = 9) + P(X = 10) = 0.1209 + 0.0480 + 0.0125 + 0.0019 + 0.0001 = 0.1834

0.1834 = 18.34% probability that the number of U.S. adults who have very little confidence in newspapers is at least​ six.

(c) less than four.

This is:

P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)

P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}

P(X = 0) = C_{10,0}.(0.41)^{0}.(0.59)^{10} = 0.0051

P(X = 1) = C_{10,1}.(0.41)^{1}.(0.59)^{9} = 0.0355

P(X = 2) = C_{10,2}.(0.41)^{2}.(0.59)^{8} = 0.1111

P(X = 3) = C_{10,3}.(0.41)^{3}.(0.59)^{7} = 0.2058

So

P(X < 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) = 0.0051 + 0.0355 + 0.1111 + 0.2058 = 0.3575

0.3575 = 35.75% probability that the number of U.S. adults who have very little confidence in newspapers is less than four.

You might be interested in
To get the value of an expression you add
frez [133]
When we substitute a specific valuefor each variable, and then perform the operations, it's called evaluating theexpression. Let's evaluate theexpression 3y + 2y when 5 = y. Click on the steps to see how it's done. Perform the operations, to find the value of the expression.
6 0
3 years ago
Read 2 more answers
Help with practice problem
padilas [110]

Answer:

attached above with detail explanation.

5 0
2 years ago
12y+15=24-6y ??????????????????
lyudmila [28]

Answer:y=1/2

Step-by-step explanation:

7 0
3 years ago
What is the value of x? <br>10<br>15<br>30<br>45​
DochEvi [55]
X is 0,in most situations,but could you provide a picture next time?
3 0
3 years ago
A pair of pants originally cost $15 and are 10% off. In addition, you have a coupon to get another 20% off. How much will the pa
GalinKa [24]
I believe it is 10.50
8 0
3 years ago
Read 2 more answers
Other questions:
  • Solve the equation. y + 3 = –y + 9
    12·2 answers
  • A blank is a unit rate with a denominator of unit 1. What word is the blank?
    11·1 answer
  • May I Please Get Help With Questions 2 and 4
    11·1 answer
  • Find the standard deviation, _, for the binomial distribution which has the stated values of n and p. n=38; p=2/5
    15·1 answer
  • How do I get my answer to this question
    7·2 answers
  • Kendra made a bar graph showing the number of hours she spent doing homework for different school subjects last month. How many
    12·1 answer
  • Solve for x.<br> X 4/5/15
    10·1 answer
  • Addison invested $440 in an account paying an interest rate of 2%
    10·2 answers
  • PLEASE HELP HELP ME HELP ME HELP ME ITS MATH EZ STUFF
    12·2 answers
  • What number decreased by 5% of itself equals 703?
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!