Skip to main content
Ch. 5 - Discrete Probability Distributions
Triola - Elementary Statistics 14th Edition
Triola14th EditionElementary StatisticsISBN: 9780137366446Not the one you use?Change textbook
Chapter 5, Problem 5.1.20d

Using Probabilities for Significant Events


d. Is 1 a significantly low number of matches? Why or why not?

Verified step by step guidance
1
Step 1: Understand the concept of 'significantly low' in statistics. A number is considered significantly low if its probability of occurrence is very small, typically less than or equal to 0.05 (5%). This threshold is often used in hypothesis testing.
Step 2: Identify the probability distribution that governs the number of matches in the given scenario. For example, it could be a binomial distribution, Poisson distribution, or another relevant model depending on the context of the problem.
Step 3: Calculate the probability of observing exactly 1 match using the appropriate probability formula for the identified distribution. For instance, if it's a binomial distribution, use the formula: P(X=1)=(n!)/(k!(n-k)!)×pk×(1-p)n-k, where n is the number of trials, k is the number of successes, and p is the probability of success.
Step 4: Compare the calculated probability of observing 1 match to the significance threshold (e.g., 0.05). If the probability is less than or equal to the threshold, then 1 match is considered significantly low. Otherwise, it is not.
Step 5: Provide reasoning based on the comparison. If the probability is significantly low, explain that this indicates the event is unlikely to occur under normal circumstances. If it is not significantly low, explain that the event is within the range of expected outcomes.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Significance Level

The significance level, often denoted as alpha (α), is a threshold used in hypothesis testing to determine whether to reject the null hypothesis. Commonly set at 0.05, it represents the probability of making a Type I error, which occurs when a true null hypothesis is incorrectly rejected. Understanding this concept is crucial for assessing whether a result, such as the number of matches, is statistically significant.
Recommended video:
Guided course
04:46
Step 4: State Conclusion Example 4

Statistical Power

Statistical power is the probability that a test will correctly reject a false null hypothesis. It is influenced by the sample size, effect size, and significance level. A low number of matches, like 1, may lead to low power, making it difficult to detect a true effect if one exists. This concept helps in evaluating whether the observed number of matches is sufficient to draw meaningful conclusions.
Recommended video:
Guided course
05:53
Parameters vs. Statistics

Contextual Interpretation of Data

Contextual interpretation involves analyzing data within the framework of the specific situation or experiment. In this case, determining whether 1 match is significantly low requires understanding the expected number of matches based on prior data or theoretical models. This concept emphasizes that statistical results should not be viewed in isolation but rather in relation to the broader context of the study.
Recommended video:
Guided course
04:39
Visualizing Qualitative vs. Quantitative Data
Related Practice
Textbook Question

In Exercises 6–10, refer to the accompanying table, which describes the numbers of adults in groups of five who reported sleepwalking (based on data from “Prevalence and Comorbidity of Nocturnal Wandering In the U.S. Adult General Population,” by Ohayon et al., Neurology, Vol. 78, No. 20).



Probability Find the probability that at least one of the subjects is a sleepwalker.

158
views
Textbook Question

In Exercises 25–28, find the probabilities and answer the questions.



Too Young to Tat Based on a Harris poll, among adults who regret getting tattoos, 20% say that they were too young when they got their tattoos. Assume that five adults who regret getting tattoos are randomly selected, and find the indicated probability.


d. If we randomly select five adults, is 1 a significantly low number who say that they were too young to get tattoos?

131
views
Textbook Question

Expected Value in North Carolina’s Pick 4 Game In North Carolina’s Pick 4 lottery game, you can pay \(1 to select a four-digit number from 0000 through 9999. If you select the same sequence of four digits that are drawn, you win and collect \)5000.


e. If you bet \$1 in North Carolina’s Pick 3 game, the expected value is Which bet is better in the sense of a producing a higher expected value: A \$1 bet in the North Carolina Pick 4 game or a \$1 bet in the North Carolina Pick 3 game?

179
views
Textbook Question

Politics The County Clerk in Essex, New Jersey, was accused of cheating by not using randomness in assigning the order in which candidates’ names appeared on voting ballots. Among 41 different ballots, Democrats were assigned the desirable first line 40 times. Assume that Democrats and Republicans are assigned the first line using a method of random selection so that they are equally likely to get that first line.


e. What do the results suggest about how the clerk met the requirement of using a random method to assign the order of candidates’ names on voting ballots?

106
views
Textbook Question

Expected Value for the Florida Pick 3 Lottery In the Florida Pick 3 lottery, you can bet \$1 by selecting three digits, each between 0 and 9 inclusive. If the same three numbers are drawn in the same order, you win and collect \(500.


d. Find the expected value for a \)1 bet.

189
views
Textbook Question

Expected Value in North Carolina’s Pick 4 Game In North Carolina’s Pick 4 lottery game, you can pay \(1 to select a four-digit number from 0000 through 9999. If you select the same sequence of four digits that are drawn, you win and collect \)5000.


d. Find the expected value.

150
views