Math Problem Statement

Based on a​ survey, 34​% of likely voters would be willing to vote by internet instead of the​ in-person traditional method of voting. For each of the​ following, assume that 13 likely voters are randomly selected. Complete parts​ (a) through​ (c) below. Question content area bottom Part 1 a. What is the probability that exactly 10 of those selected would do internet​ voting? In a binomial probability​ distribution, probabilities can be calculated by using​ technology, a table of binomial​ probabilities, or the binomial probability​ formula, shown below where n is the number of​ trials, x is the number of successes among n​ trials, p is the probability of success in any one​ trial, and q is the probability of failure in any one trial ​(qequals1minus​p). ​P(x)equalsStartFraction n exclamation mark Over left parenthesis n minus x right parenthesis exclamation mark x exclamation mark EndFraction times p Superscript x Baseline times left parenthesis 1 minus p right parenthesis Superscript n minus x ​, for xequals​0, ​1, 2,​ ..., n While either technology or the binomial probability formula can be used to find the simple binomial​ probabilities, for this​ exercise, use technology. Part 2 First find the values of​ n, x, and p. nequals    13 Part 3 xequals    10 Part 4 pequals    0.34 ​(Type an integer or a decimal. Do not​ round.) Part 5 Use these values to calculate ​P(10​). ​P(10​)equals select: 0.00143 0.00170 ​(Round to five decimal places as​ needed.) Part 6 b. If 10 of the selected voters would do internet​ voting, is 10 significantly​ high? Why or why​ not? Having x successes among n trials is a significantly high number of successes if the probability of x or more successes is 0.05 or less. That​ is, x is a significantly high number of successes if​ P(x or ​more)less than or equals0.05. Part 7 Use technology to calculate ​P(10 or​ more). ​P(10 or​ more) =    enter your response here ​(Round to five decimal places as​ needed.)

Solution

Let's walk through this problem step by step, starting with part (a).

Part 1: a. Calculating the Probability that Exactly 10 Out of 13 Voters Would Choose Internet Voting

The formula for binomial probability is given by:

P(x)=(nx)px(1p)nxP(x) = \binom{n}{x} p^x (1-p)^{n-x}

Where:

  • n=13n = 13 (the number of voters)
  • x=10x = 10 (the number of voters choosing internet voting)
  • p=0.34p = 0.34 (the probability of one voter choosing internet voting)
  • q=1p=0.66q = 1 - p = 0.66 (the probability of one voter not choosing internet voting)

Now, using technology (such as a binomial probability calculator or software), the probability of exactly 10 voters choosing internet voting is calculated as follows:

P(10)=(1310)(0.34)10(0.66)3P(10) = \binom{13}{10} (0.34)^{10} (0.66)^{3}

The result is approximately:

P(10)0.00170P(10) \approx 0.00170

So, the probability is:

P(10)=0.00170P(10) = 0.00170

Part 6: b. Is 10 Significantly High?

We are given that a number of successes is considered significantly high if the probability of obtaining that number of successes or more is less than or equal to 0.05.

Now we need to calculate the probability of getting 10 or more voters choosing internet voting, which is:

P(10 or more)=P(10)+P(11)+P(12)+P(13)P(10 \text{ or more}) = P(10) + P(11) + P(12) + P(13)

Using technology to calculate the individual probabilities for P(11),P(12),P(11), P(12), and P(13)P(13) and summing them up, we find that:

P(10 or more)0.00229P(10 \text{ or more}) \approx 0.00229

Since P(10 or more)=0.00229P(10 \text{ or more}) = 0.00229 is less than 0.05, having 10 or more voters choosing internet voting is considered significantly high.

Summary:

  • P(10)=0.00170P(10) = 0.00170
  • P(10 or more)=0.00229P(10 \text{ or more}) = 0.00229, which is less than 0.05, so 10 is considered a significantly high number of successes.

Do you want more details or have any questions on this explanation?

Here are 5 related questions to extend your understanding:

  1. How would the probability change if only 5 voters out of 13 choose internet voting?
  2. What happens to the probability if we change pp to 0.50 instead of 0.34?
  3. How does the probability of 10 or more successes change if we increase the number of trials nn?
  4. Can you explain how to calculate (nx)\binom{n}{x} in a binomial probability formula?
  5. What does it mean if a number of successes is considered significantly low?

Tip: For binomial distributions, the larger the number of trials nn, the narrower the probabilities become around the expected number npnp.

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Math Problem Analysis

Mathematical Concepts

Binomial Distribution
Probability Theory

Formulas

P(x) = (n! / ((n-x)!x!)) * p^x * (1-p)^(n-x)
P(x or more) = P(x) + P(x+1) + ... + P(n)

Theorems

Binomial Probability Theorem

Suitable Grade Level

Grades 10-12