Final Stats

(T or F) A correlation coefficient of 0.961 would mean that the values of x increase as the values of y decrease.

False

(T or F) Based on her electric bills from last year, Mrs. Smith expects she will be paying $75/month this year. This is an example of descriptive statistics

False

(T or F) For a given data set, the ogive and the frequency polygon will have the same overall shape.

False

(T or F) In a goodness of fit test the degrees of freedom are equal to the number of categories minus two.

False

(T or F) The area under the normal distribution curve that lies within three standard deviations of the mean is approximately 95%.

False

(T or F) The chi-square goodness-of-fit test is always one-tailed left.

False

(T or F) The standard deviation of sample mean will be larger than the standard deviation of the population

False

(T or F) The standard error of the estimate is the standard deviation of the observed x-values about the predicted x' values.

False

(T or F) Using a regression of y'=17.3 + 3.4x, a value of x=3.6 would result in a predicted value of y'=31.7.

False

(T or F) When the outcome of event A does not affect the probability of the outcome of a subsequent event B, then the events are said to be dependent.

False

(T or F) The range of the correlation coefficient is from 0 to 1.

False. -1 to 1

Are the following Ho:=9 and H1: does not equal 9 valid null and alternative hypotheses?

No, there are no parameters contained in these statements.

What type of sampling is being employed if the country is divided into economic classes and a sample is chosen from each class to be surveyed?

Stratified sampling

(T or F) A interval estimate may or may not contain the true value of the parameter being estimated.

True

(T or F) Chebyshev's theorem can be used to find the minimum percentage of the values in a data set that will fall within a certain distance of the mean.

True

(T or F) Frequencies obtained by calculation are called expected frequencies.

True

(T or F) If the null hypothesis is not rejected when it is false, a type II error has occurred.

True

(T or F) Inferential statistics is based on probability

True

(T or F) Questioning every 14th customer leaving a theatre about the movie they had seen, would be an example of systematic samplings

True

(T or F) Rating a restaurant by a number of stars is an example of an ordinal level of measurement.

True

(T or F) Regression is a statistical method used to describe the nature of the relationship between variables.

True

(T or F) Samples are independent when they are not related.

True

(T or F) The frequency polygon is a graph that displays the data by using lines that connect points plotted for the frequencies at the midpoints of the classes

True

(T or F) The median can be a more appropriate measure of central tendency if the data set contains outliers.

True

(T or F) The null hypothesis states that there is no difference between a parameter and a specific value, or that there is no difference between two parameters.

True

(T or F) The sum of the probabilities of all the events in the sample space of a proability distribution must equal 1.

True

(T or F) The t-distribution has a variance that is greater than one.

True

(T or F) Two events are mutually exclusive if they cannot both occur at the same time.

True

The probability of a type I error is represented by which of the following symbols?

a

The amount of time needed to run the Boston marathon is an example of which type of variable?

continuous

An independent variable can also be called a(n)

explanatory variable

The size of the box in a boxplot shows the ________ of the data set.

interquartile range

Classifying the fruit in a basket as apple, orange, or banana, is an example of the ___________ level of measurement?

nominal

A television station interviews five movie viewers after the first showing of a movie. After finding out that all five enjoyed the movie very much, the reporter states that this movie will definitely be a big hit. This is an example of ________.

suspect samples

What is the set of all possible outcomes of a probability experiment?

the sample space

One normal curve has a mean of 24 and a standard deviation of 3. A second normal curve has a mean of 3 and a standard deviation of 24. The curve that is more dispersed, or spread out, is

the second normal curve

A characteristic or measure obtained by using all the data values for a specific population is called a _____.

variable

The number of standard deviations a particular X value is from the mean is commonly referred to as ________.

z