Bus. Stats Exam 1

For the standard normal probability distribution, the area to the left of the mean is a. -0.5 b. 0.5 c. any value between 0 to 1 d. 1

0.5

The probability distribution of all possible values of the sample mean is called the a. central probability distribution b. sampling distribution of the sample mean c. random variation d. standard error

sampling distribution of the sample mean

The absolute value of the difference between the point estimate, such as the sample mean, and the value of the population parameter it estimates, such as the population mean, is known as the a. confidence level b. sampling error c. parameter estimate d. interval estimate

sampling error

Which of the following symbols represents the size of the population? a. o 2 b. o c. u d. N

N

Excel's __________ function can be used to compute the population variance. a. VARIANCE b. STDEV c. VAR d. None of the other answers are correct.

None of the above

The mean of a standard normal probability distribution a. is always equal to 1 b. can be any value as long as it is positive c. can be any value d. None of the alternative answers is correct.

None of the alternative answers is correct.

Excel's __________ function can be used to compute the sample standard deviation. a. STDEVP b. STANDARDIZE c. STANDARD d. STDEV

Stdev

Data collected at the same, or approximately the same, point in time are a. time series data b. approximate time series data c. cross-sectional data d. approximate data

cross-sectional data

76. Excel's NORMDIST function can be used to compute a. cumulative probabilities for a standard normal z value b. the standard normal z value given a cumulative probability c. cumulative probabilities for a normally distributed x value d. the normally distributed x value given a cumulative probability

cumulative probabilities for a normally distributed x value

In a standard normal distribution, the range of values of z is from a. minus infinity to infinity b. -1 to 1 c. 0 to 1 d. -3.09 to 3.09

minus infinity to infinity

A population where each element of the population is assigned to one and only one of several classes or categories is a a. multinomial population b. Poisson population c. normal population d. None of these alternatives is correct.

multinomial population

Which of the following symbols represents the size of the sample? a. o 2 b. o c. N d. n

n

The numerical value of the standard deviation can never be a. larger than the variance b. zero c. negative d. all of these statements are correct

negative

The population variance can never be a. zero b. larger than the standard deviation c. negative d. all of these are correct

negative

An important application of the chi-square distribution is a. making inferences about a single population variance b. testing for goodness of fit c. testing for the independence of two variables d. All of these alternatives are correct.

All of these alternatives are correct.

Since the population size is always larger than the sample size, then the sample statistic a. can never be larger than the population parameter b. can never be equal to the population parameter c. can never be zero d. None of the other answers are correct.

None of the other answers are correct.

The mean of the sample a. is always larger than the mean of its' population b. is always smaller than the mean of its' population c. can never be zero d. None of the other answers are correct.

None of the other answers are correct.

A population where each element of the population is assigned to one and only one of several classes or categories is a a. multinomial population b. Poisson population c. normal population d. None of these alternatives is correct.

Poisson population

Which of the following is not a characteristic of the normal probability distribution? a. The mean, median, and the mode are equal b. The mean of the distribution can be negative, zero, or positive c. The distribution is symmetrical d. The standard deviation must be 1

The standard deviation must be 1

A control chart that is used when the output of a production process is measured in terms of the percent defective is a. a P chart b. an X bar chart c. a process chart d. None of these alternatives is correct.

a P chart

The uniform probability distribution is used with a. a continuous random variable b. a discrete random variable c. a normally distributed random variable d. any random variable

a continuous random variable

The weight of an object, measured in grams, is an example of a. a continuous random variable b. a discrete random variable c. either a continuous or a discrete random variable, depending on the weight of the object d. either a continuous or a discrete random variable depending on the units of measurement

a continuous random variable

A standard normal distribution is a normal distribution with a. a mean of 1 and a standard deviation of 0 b. a mean of 0 and a standard deviation of 1 c. any mean and a standard deviation of 1 d. any mean and any standard deviation

a mean of 0 and a standard deviation of 1

A numerical measure from a population, such as a population mean, is called a. a statistic b. a parameter c. a sample d. the mean deviation

a parameter

A single numerical value used as an estimate of a population parameter is known as a. a parameter b. a population parameter c. both a parameter or a population parameter are correct d. a point estimate

a point estimate

An interval estimate is used to estimate a. the shape of the population's distribution b. the sampling distribution c. a sample statistic d. a population parameter

a population parameter

Temperature is an example of a. a qualitative variable b. a quantitative variable c. either a quantitative or qualitative variable d. neither a quantitative nor qualitative variable

a quantitative variable

A portion of the population selected to represent the population is called a. statistical inference b. descriptive statistics c. a census d. a sample

a sample

A numerical measure from a sample, such as a sample mean, is known as a. a statistic b. a parameter c. the mean deviation d. the central limit theorem

a statistic

The sampling error is the a.same as the standard error b. absolute value of the difference between an unbiased point estimate and the corresponding population parameter c. error caused by selecting a bad sample d. standard deviation multiplied by the sample size

absolute value of the difference between an unbiased point estimate and the corresponding population parameter

A continuous random variable may assume a. all values in an interval or collection of intervals b. only integer values in an interval or collection of intervals c. only fractional values in an interval or collection of intervals d. all the positive integer values in an interval

all values in an interval or collection of intervals

Whenever the population has a normal probability distribution, the sampling distribution of xbar is a normal probability distribution for a. only large sample sizes b. only small sample sizes c. any sample size d. only samples of size thirty or greater

any sample size

For a population with an unknown distribution, the form of the sampling distribution of the sample mean is a. approximately normal for all sample sizes b. exactly normal for large sample sizes c. exactly normal for all sample sizes d. approximately normal for large sample sizes

approximately normal for large sample sizes

qualitative data a.are always non-numeric b.may be either numeric or non-numeric c.are always numeric d.are always labels

are always numeric

Variations in process output that are due to factors such as machine tools wearing out are a. common causes b. assignable causes c. control causes d. None of these alternatives is correct.

assignable causes

In order not to violate the requirements necessary to use the chi-square distribution, each expected frequency in a goodness of fit test must be a. at least 5 b. at least 10 c. no more than 5 d. less than 2

at least 5

The value of the sum of the squared deviations from the mean, i.e., must always be a. less than the mean b. negative c. either positive or negative depending on whether the mean is negative or positive d. at least zero

at least zero

Since a sample is a subset of the population, the sample mean a. is always smaller than the mean of the population b. is always larger than the mean of the population c. must be equal to the mean of the population d. can be larger, smaller, or equal to the mean of the population

can be larger, smaller, or equal to the mean of the population

The variance of the sample a. can never be negative b. can be negative c. cannot be zero d. cannot be less than one

can never be negative

A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as the a. approximation theorem b. normal probability theorem c. central limit theorem d. central normality theorem

central limit theorem

Normal or natural variations in process outputs that are due purely to chance are a. common causes b. assignable causes c. control causes d. None of these alternatives is correct.

common causes

The mean of a sample is a. always equal to the mean of the population b. always smaller than the mean of the population c. computed by summing the data values and dividing the sum by (n -1) d. computed by summing all data values and dividing it by the number of items

computed by summing all data values and dividing it by the number of items

The confidence associated with an interval estimate is called the a. level of significance b. degree of association c. confidence level d. precision

confidence level

An experiment consists of measuring the speed of automobiles on a highway by the use of radar equipment. The random variable in this experiment is speed, measured in miles per hour. This random variable is a a. discrete random variable b. continuous random variable c. complex random variable d. None of the answers is correct.

continuous random variable

The sample variance a. is always smaller than the true value of the population variance b. is always larger than the true value of the population variance c. could be smaller, equal to, or larger than the true value of the population variance d. can never be zero

could be smaller, equal to, or larger than the true value of the population variance

The sum of deviations of the individual data elements from their mean is a. always greater than zero b. always less than zero c. sometimes greater than and sometimes less than zero, depending on the data d. always equal to zero

d

As the sample size increases, the margin of error a. increases b. decreases c. stays the same d. None of the other answers are correct.

decreases

As the sample size increases, the variability among the sample means a. increases b. decreases c. remains the same d. depends upon the specific population being sampled

decreases

An example of statistical inference is a. a population mean b. descriptive statistics c. calculating the size of a sample d. hypothesis testing

descriptive stats.

A statistical test conducted to determine whether to reject or not reject a hypothesized probability distribution for a population is known as a a. contingency test b. probability test c. goodness of fit test d. None of these alternatives is correct.

goodness of fit test

An estimate of a population parameter that provides an interval believed to contain the value of the parameter is known as the a. confidence level b. interval estimate c. parameter value d. population estimate

interval estimate

A normal probability distribution a. is a continuous probability distribution b. is a discrete probability distribution c. can be either continuous or discrete d. always has a standard deviation of 1

is a continuous probability distribution

The sampling distribution of the sample mean a. is the probability distribution showing all possible values of the sample mean b. is used as a point estimator of the population mean u c. is an unbiased estimator d. shows the distribution of all possible values of u

is the probability distribution showing all possible values of the sample mean

If the lower-control limit of a P chart is negative, a. a mistake has been made in the computations b. use the absolute value of the lower limit c. it is set to zero d. None of these alternatives is correct.

it is set to zero

A group of items such as incoming shipments of raw material is called a(n) a. sample plan b. incoming control c. lot d. None of these alternatives is correct.

lot

Qualitative data a.are always nonnumeric b.may be either numeric or nonnumeric c.are always numeric d.indicate either how much or how many

may be either numeric or nonnumeric

If a hypothesis is rejected at a 5% level of significance, it a. will always be rejected at the 1% level b. will always be accepted at the 1% level c. will never be tested at the 1% level d. may be rejected or not rejected at the 1% level

may be rejected or not rejected at the 1% level

The number of degrees of freedom for the appropriate chi-square distribution in a test of independence is a. n-1 b. K-1 c. number of rows minus 1 times number of columns minus 1 d. a chi-square distribution is not used

number of rows minus 1 times number of columns minus 1

A sample statistic, such as xbar , that estimates the value of the corresponding population parameter is known as a a. point estimator b. parameter c. population parameter d. Both a parameter and a population parameter are correct.

point estimator

The purpose of statistical inference is to provide information about the a. sample based upon information contained in the population b. population based upon information contained in the sample c. population based upon information contained in the population d. mean of the sample based upon the mean of the population

population based upon information contained in the sample

A numerical measure, such as a mean, computed from a population is known as a a. population parameter b. sample parameter c. sample statistic d. sample mean

population parameter

u is an example of a a. population parameter b. sample statistic c. population variance d. mode

population parameter

For ease of data entry into a university database, 1 denotes that the student is an undergraduate and 2 indicates that the student is a graduate student. In this case data are a. qualitative b. quantitative c. either qualitative or quantitative d. neither qualitative nor quantitative

qualitative

A numerical measure computed from a sample, such as sample mean, is known as a a. population parameter b. sample parameter c. sample statistic d. population mean

sample statistic

A probability distribution for all possible values of a sample statistic is known as a a. sample statistic b. parameter c. simple random sample d. sampling distribution

sampling distribution

The standard deviation of all possible xbar values is called the a. standard error of proportion b. standard error of the mean c. mean deviation d. central variation

standard error of proportion

As the sample size increases, the a. standard deviation of the population decreases b. population mean increases c. standard error of the mean decreases d. standard error of the mean increases

standard error of the mean decreases

The process of analyzing sample data in order to draw conclusions about the characteristics of a population is called a. descriptive statistics b. statistical inference c. data analysis d. data summarization

statistical inference

If the variance of a data set is correctly computed with the formula using n 1 in the denominator, which of the following is true? a. the data set is a sample b. the data set is a population c. the data set could be either a sample or a population d. the data set is from a census

the data set is a sample

In the hypothesis testing procedure, a is a. the level of significance b. the critical value c. the confidence level d. level of significance

the level of significance

Which of the following does not need to be known in order to compute the p-value? a. knowledge of whether the test is one-tailed or two-tailed b. the value of the test statistic c. the level of significance d. All of these are needed.

the level of significance

In hypothesis testing, the hypothesis tentatively assumed to be true is a. the alternative hypothesis b. the null hypothesis c. either the null or the alternative d. None of the other answers are correct.

the null hypothesis

The collection of all elements of interest in a particular study is a. the population b. the sampling c. statistical inference d. descriptive statistics

the population

For a standard normal distribution, a negative value of z indicates a. a mistake has been made in computations, because z is always positive b. the area corresponding to the z is negative c. the z is to the left of the mean d. the z is to the right of the mean

the z is to the left of the mean

Data collected over several time periods are a. time series data b. time controlled data c. cross-sectional data d. time cross-sectional data

time series data

Larger values of the standard deviation result in a normal curve that is a. shifted to the right b. shifted to the left c. narrower and more peaked d. wider and flatter

wider and flatter

For any continuous random variable, the probability that the random variable takes on exactly a specific value is a. 1.00 b. 0.50 c. any value between 0 to 1 d. zero

zero