Understanding Basic Statistics
7th Edition
ISBN: 9781305254060
Author: Charles Henry Brase, Corrinne Pellillo Brase
Publisher: Cengage Learning
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Chapter 7.3, Problem 12P
Basic Computation: Find
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In Gallup's Annual Consumption Habits Poll, telephone interviews were conducted for a random sample of 1014 adults aged 18 and over. One of the questions was "How many cups of coffee, if any, do you drink on an average day?" The following table shows the results obtained (Gallup website, August 6, 2012).
Excel File: data05-23.xls
Number of Cups
per Day
Number of
Responses
0
365
264
193
2
3
4 or more
91
101
Define a random variable x = number of cups of coffee consumed on an average day. Let x = 4 represent four or more cups.
Round your answers to four decimal places.
a. Develop a probability distribution for x.
x
0
1
2
3
f(x)
b. Compute the expected value of x.
cups of coffee
c. Compute the variance of x.
cups of coffee squared
d. Suppose we are only interested in adults that drink at least one cup of coffee on an average day. For this group, let y = the number of cups of coffee consumed on an average day.
Compute the expected value of y.
Compare it to the expected value of x.
The…
A technician services mailing machines at companies in the Phoenix area. Depending on the type of malfunction, the service call can take 1, 2, 3, or 4 hours. The different types of malfunctions occur at about the same frequency.
Develop a probability distribution for the duration of a service call.
Duration of Call
x
f(x)
1
2
3
4
Which of the following probability distribution graphs accurately represents the data set?
Consider the required conditions for a discrete probability function, shown below.Does this probability distribution satisfy equation (5.1)?Does this probability distribution satisfy equation (5.2)?
What is the probability a service call will take three hours?
A service call has just come in, but the type of malfunction is unknown. It is 3:00 P.M. and service technicians usually get off at 5:00 P.M. What is the probability the service technician will have to work overtime to fix the machine today?
A psychologist determined that the number of sessions required to obtain the trust of a new patient is either 1, 2, or 3. Let x be a random variable indicating the number of sessions required to gain the patient's trust. The following probability function has been proposed.
x
f(x)
for x = 1, 2, or 3
a. Consider the required conditions for a discrete probability function, shown below.
f(x) ≥0
Σf(x) = 1
(5.1)
(5.2)
Does this probability distribution satisfy equation (5.1)?
Select
Does this probability distribution satisfy equation (5.2)?
Select
b. What is the probability that it takes exactly 2 sessions to gain the patient's trust (to 3 decimals)?
c. What is the probability that it takes at least 2 sessions to gain the patient's trust (to 3 decimals)?
Chapter 7 Solutions
Understanding Basic Statistics
Ch. 7.1 - Statistical Literacy Which, if any, of the curves...Ch. 7.1 - Statistical Literacy Look at the normal curve in...Ch. 7.1 - Critical Thinking Look at the two normal curves in...Ch. 7.1 - Critical Thinking Sketch a normal curve (a) with...Ch. 7.1 - Basic Computation: Empirical Rule What percentage...Ch. 7.1 - Basic Computation: Empirical Rule What percentage...Ch. 7.1 - Distribution: Heights of Coeds Assuming that the...Ch. 7.1 - Distribution: Rhode Island Red Chicks The...Ch. 7.1 - Archaeology: Tree Rings At Burnt Mesa Pueblo,...Ch. 7.1 - Vending Machine: Soft Drinks A vending machine...
Ch. 7.1 - Pain Management: Laser Therapy Effect of...Ch. 7.1 - Expand Your knowledge: Continuous Uniform...Ch. 7.1 - Unifrom Distribution: Measurement Errors...Ch. 7.2 - Statistical Literacy What does a standard score...Ch. 7.2 - Statistical Literacy Does a raw score less than...Ch. 7.2 - Statistical Literacy What is the value of the...Ch. 7.2 - Statistical Literacy What are the values of the...Ch. 7.2 - Basic Computation: z Score and Raw Score A normal...Ch. 7.2 - Basic Computation: z Score and Raw Score A normal...Ch. 7.2 - Critical Thinking Consider the following scores:...Ch. 7.2 - Critical Thinking Raul received a score of 80 on a...Ch. 7.2 - z Scores: First Aid Course The college physical...Ch. 7.2 - z Scores: Fawns Fawns between 1 and 5 months old...Ch. 7.2 - Prob. 11PCh. 7.2 - Normal Curve: Tree Rings Tree-ring dates were used...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Prob. 22PCh. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Areas Under the...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.2 - Basic Computation: Finding Probabilities In...Ch. 7.3 - Statistical Literacy Consider a normal...Ch. 7.3 - Statistical Literacy Suppose 5% of the area under...Ch. 7.3 - Statistical Literacy Suppose 5% of the area under...Ch. 7.3 - Critical Thinking: Normality Consider the...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find Probabilities In Problems...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Basic Computation: Find zValues In Problems 15-24,...Ch. 7.3 - Medical: Blood Glucose A person's blood glucose...Ch. 7.3 - Medical: Blood Protoplasm Porphyrin is a pigment...Ch. 7.3 - 27 Archaeology: Hopi Village Thickness...Ch. 7.3 - Law Enforcement: Police Response Time Police...Ch. 7.3 - Guarantee: Batteries Quick Start Company makes...Ch. 7.3 - Guarantee: Watches Accrotime is a manufacturer of...Ch. 7.3 - Expand Your Knowledge: Estimating the Standard...Ch. 7.3 - Estimating the Standard Deviation: Refrigerator...Ch. 7.3 - Estimating the Standard Deviation: Veterinary...Ch. 7.3 - Estimating the Standard Deviation: Veterinary...Ch. 7.3 - Insurance: Satellites A relay microchip in a...Ch. 7.4 - Statistical Literacy What is a population? Give...Ch. 7.4 - Statistical Literac y What is a random sample from...Ch. 7.4 - Statistical Literacy What is a population...Ch. 7.4 - Statistical Literacy What is a sample statistic?...Ch. 7.4 - Statistical Literacy What is the meaning of the...Ch. 7.4 - Statistical Literacy What is a sampling...Ch. 7.4 - Critical Thinking How do frequency tables,...Ch. 7.4 - Critical Thinking How can relative frequencies be...Ch. 7.4 - Critical Thinking Give an example of a specific...Ch. 7.5 - Statistical Literacy What is the standard error of...Ch. 7.5 - Statistical Literacy What is the standard...Ch. 7.5 - Statistical Literacy List two unbiased estimators...Ch. 7.5 - Statistical Literacy Describe how the variability...Ch. 7.5 - Basic Computation: Central Limit Theorem Suppose x...Ch. 7.5 - Basic Computation: Central Limit Theorem Suppose x...Ch. 7.5 - Prob. 7PCh. 7.5 - Critical Thinking Suppose x has a distribution...Ch. 7.5 - Critical Thinking Consider two x distributions...Ch. 7.5 - Critical Thinking Consider an x distribution with...Ch. 7.5 - Critical Thinking Suppose x has a distribution...Ch. 7.5 - Critical Thinking Suppose an x distribution has...Ch. 7.5 - Coal: Automatic Loader Coal is carried from a mine...Ch. 7.5 - Vital Statistics: Heights of Men The heights of...Ch. 7.5 - Medical: Blood Glucose Let x be a random variable...Ch. 7.5 - Medical: White Blood Cells Let x be a random...Ch. 7.5 - Wildlife: Deer Let x be a random variable that...Ch. 7.5 - Focus Problem: Impulse Buying Let x represent the...Ch. 7.5 - Finance: Templeton Funds Templeton world is a...Ch. 7.5 - Finance: European Growth Fund A European growth...Ch. 7.6 - Statistical Literacy Binomial probability...Ch. 7.6 - Statistical Literacy When we use a normal...Ch. 7.6 - Basic Computation: Normal Approximation to a...Ch. 7.6 - Basic Computation: Normal Approximation to a...Ch. 7.6 - Critical Thinking You need to compute the...Ch. 7.6 - Critical Thinking Consider a binomial experiment...Ch. 7.6 - In the following problems, check that it is...Ch. 7.6 - Insurance: Claims Do you try to pad an insurance...Ch. 7.6 - Longevity: 90th Birthday It is estimated that 3.5%...Ch. 7.6 - Fishing: Billfish Ocean fishing for billfish is...Ch. 7.6 - Grocery Stores: New ProductsThe Denver Post slated...Ch. 7.6 - Crime: Murder What are the chances that a person...Ch. 7.6 - Supermarkets: Free Samples Do you take the free...Ch. 7.6 - Ice Cream: Flavors Whats your favorite ice cream...Ch. 7.6 - Airline Flights: No-Shows Based on long...Ch. 7.6 - 16. General: Approximations We have studied the...Ch. 7.6 - Statistical Literacy Under what conditions is it...Ch. 7.6 - Statistical Literacy What is the formula for the...Ch. 7.6 - Statistical Literacy Is p an unbiased estimator...Ch. 7.6 - Basic Computation: p Distribution Suppose we have...Ch. 7.6 - Basic Computation: p Distribution Suppose we have...Ch. 7 - Statistical Literacy Describe a normal probability...Ch. 7 - Statistical Literacy According to the empirical...Ch. 7 - Statistical Literacy Random sample of size 9 is...Ch. 7 - Statistical Literacy Can a normal distribution...Ch. 7 - Statistical Literacy What characteristic of a...Ch. 7 - Statistical Liter acy For a normal distribution,...Ch. 7 - Statistical Literacy Give the formula for the...Ch. 7 - Statistical Literacy Give the formula for the...Ch. 7 - Critical Thinking Let x be a random variable...Ch. 7 - Critical Thinking If x has a normal distribution...Ch. 7 - Basic Computation: Probability Given that x is a...Ch. 7 - Basic Computation: Probability Given that x is a...Ch. 7 - Basic Computation: Inverse Normal Find z such that...Ch. 7 - Basic Computation: Inverse Normal Find z such that...Ch. 7 - Medical: Blood Type Blood type AB is found in only...Ch. 7 - Customer Complaints: Time The Customer Service...Ch. 7 - 21. Recycling: Aluminum Cans One environmental...Ch. 7 - Prob. 18CRCh. 7 - Guarantee: Package Delivery Express Courier...Ch. 7 - Drugs: Effects A new muscle relaxant is available....Ch. 7 - Psychology: IQ Scores Assume that IQ scores are...Ch. 7 - Hatchery Fish: Length A large tank of fish from a...Ch. 7 - Basic Computation: p Distribution Suppose we have...Ch. 7 - Green Behavior: Purchasing Habits A recent Harris...Ch. 7 - Iris setosa is a beautiful wildflower that is...Ch. 7 - If you look up the word empirical in a dictionary,...Ch. 7 - Why are standard z values so important? Is it true...Ch. 7 - Most people would agree that increased information...Ch. 7 - In a way, the central limit theorem can be thought...
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- A technician services mailing machines at companies in the Phoenix area. Depending on the type of malfunction, the service call can take 1, 2, 3, or 4 hours. The different types of malfunctions occur at about the same frequency. Develop a probability distribution for the duration of a service call. Which of the following probability distribution graphs accurately represents the data set? Consider the required conditions for a discrete probability function, shown below.Does this probability distribution satisfy equation (5.1)?Does this probability distribution satisfy equation (5.2)? What is the probability a service call will take three hours? A service call has just come in, but the type of malfunction is unknown. It is 3:00 P.M. and service technicians usually get off at 5:00 P.M. What is the probability the service technician will have to work overtime to fix the machine today?arrow_forwardWest Virginia has one of the highest divorce rates in the nation, with an annual rate of approximately 5 divorces per 1000 people (Centers for Disease Control and Prevention website, January 12, 2012). The Marital Counseling Center, Inc. (MCC) thinks that the high divorce rate in the state may require them to hire additional staff. Working with a consultant, the management of MCC has developed the following probability distribution for x = the number of new clients for marriage counseling for the next year. Excel File: data05-19.xls 10 20 f(x) .05 .10 11 30 40 50 60 .10 .20 .35 .20 a. Is this probability distribution valid? Yes Explain. greater than or equal to 0 f(x) Σf(x) equal to 1 b. What is the probability MCC will obtain more than 30 new clients (to 2 decimals)? c. What is the probability MCC will obtain fewer than 20 new clients (to 2 decimals)? d. Compute the expected value and variance of x. Expected value Variance clients per year squared clients per yeararrow_forwardReconsider the patient satisfaction data in Table 1. Fit a multiple regression model using both patient age and severity as the regressors. (a) Test for significance of regression. (b) Test for the individual contribution of the two regressors. Are both regressor variables needed in the model? (c) Has adding severity to the model improved the quality of the model fit? Explain your answer.arrow_forward
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