 9.9.1: A UCLA researcher claims that the life span of mice can be extended...
 9.9.2: An electrical rm manufactures light bulbs that have a length of lif...
 9.9.3: Many cardiac patients wear an implanted pacemaker to control their ...
 9.9.4: The heights of a random sample of 50 college students showed a mean...
 9.9.5: A random sample of 100 automobile owners in the state of Virginia s...
 9.9.6: How large a sample is needed in Exercise 9.2 if we wish to be 96% c...
 9.9.7: How large a sample is needed in Exercise 9.3 if we wish to be 95% c...
 9.9.8: An eciency expert wishes to determine the average time that it take...
 9.9E: The article “Evaluation of a Ventilation Strategy to Prevent Barotr...
 9.9.9: Regular consumption of presweetened cereals contributes to tooth de...
 9.9.10: A random sample of 12 graduates of a certain secretarial school typ...
 9.9.11: A machine produces metal pieces that are cylindrical in shape. A sa...
 9.9.12: A random sample of 10 chocolate energy bars of a certain brand has,...
 9.9.13: ?A random sample of 12 shearing pins is taken in a study of the Roc...
 9.9.14: The following measurements were recorded for the drying time, in ho...
 9.15E: a.? ?Show for the uppertailed test with ?1 and ?2 known that as ei...
 9.9.15: Referring to Exercise 9.5, construct a 99% prediction interval for ...
 9.9.16: Consider Exercise 9.10. Compute the 95% prediction interval for the...
 9.9.17: Consider Exercise 9.9. Compute a 95% prediction interval for the su...
 9.9.18: Referring to Exercise 9.13, construct a 95% tolerance interval cont...
 9.9.19: A random sample of 25 tablets of buered aspirin contains, on averag...
 9.9.20: Consider the situation of Exercise 9.11. Estimation of the mean dia...
 9.9.21: In a study conducted by the Department of Zoology at Virginia Tech,...
 9.9.22: A type of thread is being studied for its tensile strength properti...
 9.9.23: Refer to Exercise 9.22. Why are the quantities requested in the exe...
 9.9.24: Refer to Exercise 9.22 again. Suppose that specications by a buyer ...
 9.9.25: Consider the drying time measurements in Exercise 9.14. Suppose the...
 9.9.26: Consider the data in Exercise 9.13. Suppose the manufacturer of the...
 9.9.27: Consider the situation of Case Study 9.1 on page 281 with a larger ...
 9.9.28: In Section 9.3, we emphasized the notion of most ecient estimator b...
 9.9.29: Let us dene S2 =n i=1 (Xi X)2/n. Show that E(S2) = [(n1)/n]2, and h...
 9.9.30: Consider S2, the estimator of 2, from Exercise 9.29. Analysts often...
 9.9.31: If X is a binomial random variable, show that (a) P = X/n is an unb...
 9.9.32: Show that the estimator P of Exercise 9.31(b) becomes unbiased as n
 9.9.33: Compare S2 and S2 (see Exercise 9.29), thetwo estimators of 2, to d...
 9.9.34: Consider Exercise 9.33. Use the MSE discussed in Exercise 9.28 to d...
 9.9.35: A random sample of size n1 = 25, taken from a normal population wit...
 9.9.36: Two kinds of thread are being compared for strength. Fifty pieces o...
 9.9.37: A study was conducted to determine if a certain treatment has any e...
 9.9.38: Two catalysts in a batch chemical process, are being compared for t...
 9.9.39: Students may choose between a 3semesterhour physics course withou...
 9.9.40: In a study conducted at Virginia Tech on the development of ectomyc...
 9.9.41: The following data represent the length of time, in days, to recove...
 9.9.42: An experiment reported in Popular Science compared fuel economies f...
 9.9.43: A taxi company is trying to decide whether to purchase brand A or b...
 9.9.44: Referring to Exercise 9.43, nd a 99% condence interval for 1 2 if t...
 9.9.45: The federal government awarded grants to the agricultural departmen...
 9.9.46: The following data represent the running times of lms produced by t...
 9.9.47: Fortune magazine (March 1997) reported the total returns to investo...
 9.9.48: An automotive company is considering two types of batteries for its...
 9.9.49: Two dierent brands of latex paint are being considered for use. Fif...
 9.9.50: Two levels (low and high) of insulin doses are given to two groups ...
 9.9.51: For estimation concerning one proportion, use only method 1 to obta...
 9.9.52: For estimation concerning one proportion, use only method 1 to obta...
 9.9.53: For estimation concerning one proportion, use only method 1 to obta...
 9.9.54: For estimation concerning one proportion, use only method 1 to obta...
 9.9.55: For estimation concerning one proportion, use only method 1 to obta...
 9.9.56: For estimation concerning one proportion, use only method 1 to obta...
 9.9.57: For estimation concerning one proportion, use only method 1 to obta...
 9.9.58: For estimation concerning one proportion, use only method 1 to obta...
 9.9.59: For estimation concerning one proportion, use only method 1 to obta...
 9.9.60: For estimation concerning one proportion, use only method 1 to obta...
 9.9.61: For estimation concerning one proportion, use only method 1 to obta...
 9.9.62: For estimation concerning one proportion, use only method 1 to obta...
 9.9.63: For estimation concerning one proportion, use only method 1 to obta...
 9.9.64: For estimation concerning one proportion, use only method 1 to obta...
 9.9.65: For estimation concerning one proportion, use only method 1 to obta...
 9.9.66: For estimation concerning one proportion, use only method 1 to obta...
 9.9.67: For estimation concerning one proportion, use only method 1 to obta...
 9.9.68: For estimation concerning one proportion, use only method 1 to obta...
 9.9.69: For estimation concerning one proportion, use only method 1 to obta...
 9.9.70: For estimation concerning one proportion, use only method 1 to obta...
 9.9.71: A manufacturer of car batteries claims that the batteries will last...
 9.9.72: A random sample of 20 students yielded a mean of x = 72 and a varia...
 9.9.73: Construct a 95% condence interval for 2 in Exercise 9.9 on page 283.
 9.9.74: Construct a 99% condence interval for 2 in Exercise 9.11 on page 283.
 9.9.75: Construct a 99% condence interval for in Exercise 9.12 on page 283.
 9.9.76: Construct a 90% condence interval for in Exercise 9.13 on page 283.
 9.9.77: Construct a 98% condence interval for 1/2 in Exercise 9.42 on page ...
 9.9.78: Construct a 90% condence interval for 2 1/2 2 in Exercise 9.43 on p...
 9.9.79: Construct a 90% condence interval for 2 1/2 2 in Exercise 9.46 on p...
 9.9.80: Construct a 95% condence interval for 2 A/2 B in Exercise 9.49 on p...
 9.9.81: Suppose that there are n trials x1,x2,...,xn from a Bernoulli proce...
 9.9.82: Consider the lognormal distribution with the density function given...
 9.9.83: Consider a random sample of x1,...,xn coming from the gamma distrib...
 9.9.84: Consider a random sample of x1,x2,...,xn observations from a Weibul...
 9.9.85: Consider a random sample of x1,...,xn from a uniform distribution U...
 9.9.86: Consider the independent observations x1,x2,...,xn from the gamma d...
 9.9.87: Consider a hypothetical experiment where a man with a fungus uses a...
 9.9.88: Consider the observation X from the negative binomial distribution ...
 9.9.89: Consider two estimators of 2 for a sample x1,x2,...,xn, which is dr...
 9.9.90: According to the Roanoke Times, McDonalds sold 42.1% of the market ...
 9.9.91: It is claimed that a new diet will reduce a persons weight by 4.5 k...
 9.9.92: A study was undertaken at Virginia Tech to determine if re can be u...
 9.9.93: A health spa claims that a new exercise program will reduce a perso...
 9.9.94: The Department of Civil Engineering at Virginia Tech compared a mod...
 9.9.95: An experiment was conducted to determine whether surface nish has a...
 9.9.96: An anthropologist is interested in the proportion of individuals in...
 9.9.97: A manufacturer of electric irons produces these items in two plants...
 9.9.98: It is argued that the resistance of wire A is greater than the resi...
 9.9.99: An alternative form of estimation is accomplished through the metho...
 9.9.100: Specify the moment estimators for and 2 for the normal distribution.
 9.9.101: Specify the moment estimators for and 2 for the lognormal distribut...
 9.9.102: Specify the moment estimators for and for the gamma distribution.
 9.9.103: A survey was done with the hope of comparing salaries of chemical p...
 9.9.104: Consider Review Exercise 9.103. Let us assume that the data have no...
 9.9.105: A labor union is becoming defensive about gross absenteeism by its ...
 9.9.106: A random sample of 30 rms dealing in wireless products was selected...
 9.9.107: Refer to Review Exercise 9.106. Suppose there is concern about whet...
 9.9.108: A manufacturer turns out a product item that is labeled either defe...
 9.9.109: A machine is used to ll boxes with product in an assembly line oper...
 9.9.110: A consumer group is interested in comparing operating costs for two...
 9.9.111: Consider the statistic S2 p, the pooled estimate of 2 discussed in ...
 9.9.112: A group of human factor researchers are concerned about reaction to...
 9.9.113: A certain supplier manufactures a type of rubber mat that is sold t...
Solutions for Chapter 9: Introduction to Statistics and Data Analysis
Full solutions for Probability and Statistics for Engineers and the Scientists  9th Edition
ISBN: 9780321629111
Solutions for Chapter 9: Introduction to Statistics and Data Analysis
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Alternative hypothesis
In statistical hypothesis testing, this is a hypothesis other than the one that is being tested. The alternative hypothesis contains feasible conditions, whereas the null hypothesis speciies conditions that are under test

Asymptotic relative eficiency (ARE)
Used to compare hypothesis tests. The ARE of one test relative to another is the limiting ratio of the sample sizes necessary to obtain identical error probabilities for the two procedures.

Bernoulli trials
Sequences of independent trials with only two outcomes, generally called “success” and “failure,” in which the probability of success remains constant.

Binomial random variable
A discrete random variable that equals the number of successes in a ixed number of Bernoulli trials.

Comparative experiment
An experiment in which the treatments (experimental conditions) that are to be studied are included in the experiment. The data from the experiment are used to evaluate the treatments.

Conidence interval
If it is possible to write a probability statement of the form PL U ( ) ? ? ? ? = ?1 where L and U are functions of only the sample data and ? is a parameter, then the interval between L and U is called a conidence interval (or a 100 1( )% ? ? conidence interval). The interpretation is that a statement that the parameter ? lies in this interval will be true 100 1( )% ? ? of the times that such a statement is made

Conidence level
Another term for the conidence coeficient.

Contingency table.
A tabular arrangement expressing the assignment of members of a data set according to two or more categories or classiication criteria

Critical value(s)
The value of a statistic corresponding to a stated signiicance level as determined from the sampling distribution. For example, if PZ z PZ ( )( .) . ? =? = 0 025 . 1 96 0 025, then z0 025 . = 1 9. 6 is the critical value of z at the 0.025 level of signiicance. Crossed factors. Another name for factors that are arranged in a factorial experiment.

Curvilinear regression
An expression sometimes used for nonlinear regression models or polynomial regression models.

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.

Density function
Another name for a probability density function

Discrete uniform random variable
A discrete random variable with a inite range and constant probability mass function.

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

Estimate (or point estimate)
The numerical value of a point estimator.

Estimator (or point estimator)
A procedure for producing an estimate of a parameter of interest. An estimator is usually a function of only sample data values, and when these data values are available, it results in an estimate of the parameter of interest.

Expected value
The expected value of a random variable X is its longterm average or mean value. In the continuous case, the expected value of X is E X xf x dx ( ) = ?? ( ) ? ? where f ( ) x is the density function of the random variable X.

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.

Forward selection
A method of variable selection in regression, where variables are inserted one at a time into the model until no other variables that contribute signiicantly to the model can be found.

Fraction defective control chart
See P chart