 9.9.1: A student survey Tonya wants to estimate what proportion of the sen...
 9.9.2: Our dirty little secret More than 90% of people surveyed say they a...
 9.9.3: Marijuana use A 20072008 survey of teens conducted by the Partnersh...
 9.9.4: Do you drink the cereal milk? A USA Today poll asked a random sampl...
 9.9.5: Polling women A New York Times Poll on womens issues interviewed 10...
 9.9.6: Gun violence Th e Harris Poll asked a sample of 1009 adults which c...
 9.9.7: Interpreting poll results Heres a quote from a news report about a ...
 9.9.8: Confi dence level visual Figure 9.5 (page 430) shows the meaning of...
 9.9.9: 98% confi dence Table 9.1 (page 431) gives critical values z* for s...
 9.9.10: 93% confi dence Table 9.1 (page 431) gives critical values z* for s...
 9.9.11: Going to the prom Th e prom committee of Exercise 9.1 (page 425) wa...
 9.9.12: Random digits We know that the proportion of 0s among a large set o...
 9.9.13: Determining sample size, I Suppose a polling organization wants to ...
 9.9.14: Determining sample size, II Suppose a polling organization wants to...
 9.9.15: The good life Roper ASW, a market research and consulting firm, con...
 9.9.16: Losing weight A Gallup Poll in November 2008 found that 59% of the ...
 9.9.17: Harley motorcycles HarleyDavidson motorcycles make up 14% of all t...
 9.9.18: Th e quick method Th e quick method of Section 5.2 uses 1y!n as a r...
 9.9.19: Do college students pray? Social scientists asked 127 undergraduate...
 9.9.20: Wildlife management Wildlife biologists know that males of most big...
 9.9.21: A fair deck? Activity 9.2A (page 438) asks you to determine whether...
 9.9.22: Free throws Activity 9.2B shows you how to use the Signifi cance Te...
 9.9.23: Fresh coff ee, I Show how to calculate the two probabilities given ...
 9.9.24: Fresh coff ee, II In Example 9.8, 72% of the subjects in the experi...
 9.9.25: Do you argue? A May 2005 Gallup Poll report on a national survey of...
 9.9.26: One potato, two potato A potato chip producer and a supplier of pot...
 9.9.27: Baggage check! Th ousands of travelers pass through Guadalajara air...
 9.9.28: Affi rmative action Th e Chronicle of Higher Education commissioned...
 9.9.29: Bullies in middle school If one study is any indication, many middl...
 9.9.30: Count Buff ons coin again Refer to Example 9.9 (page 445). (a) Cons...
 9.9.31: Pvalues and signifi cance, I A test of the null hypothesis H0 : p ...
 9.9.32: Pvalues and signifi cance, II A test of the null hypothesis H0 : p...
 9.9.33: No homework?! Mr. Starnes believes that fewer than 75% of the stude...
 9.9.34: Left ies Sally reads a newspaper report claiming that 12% of all ad...
 9.9.35: Wheres the blunder? Write a sentence or two to explain the blunder ...
 9.9.36: Is the Belgian euro coin fair? Exercise 7.23 (page 327) asked you t...
 9.9.37: Pvalues and signifi cance, III A test of the null hypothesis H0 : ...
 9.9.38: Pvalues and signifi cance, IV A test of the null hypothesis H0 : p...
 9.9.39: Are cell phones distracting? Th e American Automobile Association (...
 9.9.40: HackaShaq Any NBA fan has heard about the freethrow shooting woe...
 9.9.41: Activity 9.3 followup Refer to Activity 9.3 (page 453). Statistics...
 9.9.42: A television poll A television news program conducts a callin poll...
 9.9.43: Onlychild presidents Joe is writing a report on the backgrounds of...
 9.9.44: Who will win? A poll taken shortly before an election fi nds that 5...
 9.9.45: Dropping out Th e marginal nugget on page 455 describes an experime...
 9.9.46: Inference conditions Explain why each of the two conditions for per...
 9.9.47: Signifi cant, but important? Th e results of this experiment were s...
 9.9.48: Generalizability To what population can the results of this study b...
 9.9.49: Causation? Can we conclude that taking Zyban causes people to quit ...
 9.9.50: Pvalue or signifi cance level? In performing a signifi cance test,...
 9.9.51: Searching for signifi cance You perform 1000 signifi cance tests us...
 9.9.52: Plagiarizing An online poll posed the following question: It is now...
 9.9.53: Cholesterol and breast cancer Th e Journal of Womens Health reporte...
 9.9.54: What is signifi cance good for? Which of the following questions do...
 9.9.55: Searching for ESP A researcher looking for evidence of extrasensory...
 9.9.56: Is this convincing? You are planning to test a new vaccine for a vi...
 9.9.57: Why are larger samples better? Statisticians prefer large samples. ...
 9.9.58: Low pressure Th e Automobile Association of America (AAA) reports t...
 9.9.59: Why we seek signifi cance Asked why statistical signifi cance appea...
 9.9.60: Online directory While surfi ng the Internet one day, Raul fi nds t...
 9.9.61: Body temperature We have all heard that 98.6 degrees Fahrenheit (or...
 9.9.62: Signifi cant versus important Explain how a result can be statistic...
 9.9.63: We love football! A recent Gallup Poll conducted telephone intervie...
 9.9.64: Roulette A roulette wheel has 18 red slots among its 38 slots. You ...
 9.9.65: Senior citizens Table 2.4 (page 44) records the percent of resident...
 9.9.66: Comparing package designs A company compares two package designs fo...
 9.9.67: Online gaming, I A random sample of 1100 teenagers (aged 12 to 17) ...
 9.9.68: Online gaming, II Refer to the previous exercise. How large a sampl...
 9.9.69: Abstinence? Th e Gallup Youth Survey asked a random sample of 439 U...
 9.9.70: Alternative medicine A nationwide random survey of 1500 adults aske...
Solutions for Chapter 9: ntroduction to Inference
Full solutions for Statistics Through Applications  2nd Edition
ISBN: 9781429219747
Solutions for Chapter 9: ntroduction to Inference
Get Full SolutionsSince 70 problems in chapter 9: ntroduction to Inference have been answered, more than 16086 students have viewed full stepbystep solutions from this chapter. This textbook survival guide was created for the textbook: Statistics Through Applications, edition: 2. This expansive textbook survival guide covers the following chapters and their solutions. Chapter 9: ntroduction to Inference includes 70 full stepbystep solutions. Statistics Through Applications was written by and is associated to the ISBN: 9781429219747.

2 k factorial experiment.
A full factorial experiment with k factors and all factors tested at only two levels (settings) each.

2 k p  factorial experiment
A fractional factorial experiment with k factors tested in a 2 ? p fraction with all factors tested at only two levels (settings) each

`error (or `risk)
In hypothesis testing, an error incurred by rejecting a null hypothesis when it is actually true (also called a type I error).

Analytic study
A study in which a sample from a population is used to make inference to a future population. Stability needs to be assumed. See Enumerative study

Bimodal distribution.
A distribution with two modes

Chisquare test
Any test of signiicance based on the chisquare distribution. The most common chisquare tests are (1) testing hypotheses about the variance or standard deviation of a normal distribution and (2) testing goodness of it of a theoretical distribution to sample data

Conditional mean
The mean of the conditional probability distribution of a random variable.

Conditional probability density function
The probability density function of the conditional probability distribution of a continuous random variable.

Confounding
When a factorial experiment is run in blocks and the blocks are too small to contain a complete replicate of the experiment, one can run a fraction of the replicate in each block, but this results in losing information on some effects. These effects are linked with or confounded with the blocks. In general, when two factors are varied such that their individual effects cannot be determined separately, their effects are said to be confounded.

Control chart
A graphical display used to monitor a process. It usually consists of a horizontal center line corresponding to the incontrol value of the parameter that is being monitored and lower and upper control limits. The control limits are determined by statistical criteria and are not arbitrary, nor are they related to speciication limits. If sample points fall within the control limits, the process is said to be incontrol, or free from assignable causes. Points beyond the control limits indicate an outofcontrol process; that is, assignable causes are likely present. This signals the need to ind and remove the assignable causes.

Cook’s distance
In regression, Cook’s distance is a measure of the inluence of each individual observation on the estimates of the regression model parameters. It expresses the distance that the vector of model parameter estimates with the ith observation removed lies from the vector of model parameter estimates based on all observations. Large values of Cook’s distance indicate that the observation is inluential.

Correction factor
A term used for the quantity ( / )( ) 1 1 2 n xi i n ? = that is subtracted from xi i n 2 ? =1 to give the corrected sum of squares deined as (/ ) ( ) 1 1 2 n xx i x i n ? = i ? . The correction factor can also be written as nx 2 .

Degrees of freedom.
The number of independent comparisons that can be made among the elements of a sample. The term is analogous to the number of degrees of freedom for an object in a dynamic system, which is the number of independent coordinates required to determine the motion of the object.

Empirical model
A model to relate a response to one or more regressors or factors that is developed from data obtained from the system.

Enumerative study
A study in which a sample from a population is used to make inference to the population. See Analytic study

Error mean square
The error sum of squares divided by its number of degrees of freedom.

Error propagation
An analysis of how the variance of the random variable that represents that output of a system depends on the variances of the inputs. A formula exists when the output is a linear function of the inputs and the formula is simpliied if the inputs are assumed to be independent.

Error variance
The variance of an error term or component in a model.

Exponential random variable
A series of tests in which changes are made to the system under study

F distribution.
The distribution of the random variable deined as the ratio of two independent chisquare random variables, each divided by its number of degrees of freedom.