/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q3SE Suppose that a certain precinct ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Suppose that a certain precinct contains 350 voters, of which 250 are Democrats and 100 are Republicans. If 30 voters are chosen at random from the precinct, what is the probability that exactly 18 Democrats will be selected?

Short Answer

Expert verified

The probability of exactly 18 Democrats will be selected is 0.0579

Step by step solution

01

Given information

Total number of votes in a Precinct is 350.

The number of democrats is 250

Number of republicans is 100.

Number of voters selected are 30.

02

Compute the number of outcomes

30 votes are chosen at random from the precinct.

Therefore, there are\(^{350}{C_{30}}\)ways of selecting 30 voters from 350.

Also, there are\(^{{\bf{250}}}{{\bf{C}}_{{\bf{18}}}}\)ways of selecting 18 democrats.

For selecting exactly 18 democrats, we need to select remaining 12 voters from

100 republicans. Thus, the number of ways to select the 12 voters is \(^{100}{C_{12}}\)

03

Compute the probability 

Probability of selecting 18 democrats will be,

\(\begin{aligned}{}\frac{{^{250}{C_{18}}{ \times ^{100}}{C_{12}}}}{{^{350}{C_{30}}}} &= \frac{{\left( {\frac{{250!}}{{18!\left( {250 - 18} \right)!}}} \right)\left( {\frac{{100!}}{{12!\left( {100 - 12} \right)!}}} \right)}}{{\frac{{350!}}{{\left( {350 - 30} \right)!30!}}}}\\ &= 0.0579\end{aligned}\)

Thus, the required probability is 0.0579.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A box contains 24 light bulbs, of which two are defective. If a person selects 10 bulbs at random, without replacement, what is the probability that both defective bulbs will be selected?

Suppose that two boys named Davis, three boys named Jones, and four boys named Smith are seated at random in a row containing nine seats. What is the probability that the Davis boys will occupy the first two seats in the row, the Jones boys will occupy the next three seats, and the Smith boys will occupy the last four seats?

Three pollsters will canvas a neighborhood with 21 houses. Each pollster will visit seven of the houses. How many different assignments of pollsters to houses are possible?

Suppose that 35 people are divided in a random manner into two teams in such a way that one team contains10 people and the other team contains 25 people. What is the probability that two particular people A and B will be on the same team?

Suppose that a number x is to be selected from the real line S, and let A, B, and C be the events represented by the following subsets of S, where the notation\(\left\{ {x: - - - - - } \right\}\)denotes the set containing every point x for which the property presented following the colon is satisfied:

\(\begin{aligned}{}{\bf{A = }}\left\{ {{\bf{x:1}} \le {\bf{x}} \le {\bf{5}}} \right\}\\{\bf{B = }}\left\{ {{\bf{x:3 < x}} \le {\bf{7}}} \right\}\\{\bf{C = }}\left\{ {{\bf{x:x}} \le {\bf{0}}} \right\}\end{aligned}\)

Describe each of the following events as a set of real numbers:

\(\begin{aligned}{l}{\bf{a}}{\bf{.}}\;{{\bf{A}}^{\bf{c}}}\\{\bf{b}}{\bf{.}}\;{\bf{A}} \cup {\bf{B}}\\{\bf{c}}{\bf{.}}\;{\bf{B}} \cap {{\bf{C}}^{\bf{c}}}\\{\bf{d}}{\bf{.}}\;{{\bf{A}}^{\bf{c}}} \cap {{\bf{B}}^{\bf{c}}} \cap {{\bf{C}}^{\bf{c}}}\\{\bf{e}}{\bf{.}}\;\left( {{\bf{A}} \cup {\bf{B}}} \right) \cap {\bf{C}}\end{aligned}\)

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.