Stats final (definitions)

II

A type _ error occurs if one does not reject the null hypothesis when it is false.

I

A type _ error occurs if one rejects the null hypothesis when it is true.

Left-skewed

A distribution is ________ when the mean is to the left of the median, and the mean and the median are to the left of the mode.

False

A positive linear relationship exists when the points in a Pareto graph fall approximately in an ascending straight line. T or F

Trends

A regression line can be used to show _____ in data.

False

A type I error can occur when the null hypothesis is not rejected. True or False

True

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

4

As a researcher collects more and more data, the 95% prediction intervals in general become narrower and narrower, but the widths are always more than approximately _ times the standard error of the estimate.

Central Limit Theorem

As the sample size n increases, the shape of the distribution of the sample means taken with replacement from a population with mean μ and standard deviation σ, will approach a normal distribution. This distribution will have a mean of μ and a standard deviation of σ/sqr(n) . This is a statement of the _______________________.

True

Coefficient of determination is r^2 True or False

True

Coefficient of non-determination is 1-r^2 True or False

Z interval

For confidence intervals using standard deviation of population use _-_______

positively skewed

Identify the type of distribution pattern that occurs when the majority of the data values fall to the left of the mean?

(0.790)^2

If the correlation coefficient is 0.790, what is the explained variation?

True

In applied statistics, it is the area under the normal distribution curve which is most important, not the value of single points on the curve. T or F

False

Sandra Johnson, a researcher, believes her pulse rate will decrease with exercise. Her alternative hypothesis would contain an equal sign. True or False

probability

Stating that the area under the standard normal distribution curve between z = 0 and z = 1.00 is 0.3413, is the same as stating that the _____________ of randomly selecting a standard normally distributed variable z with a value between 0 and 1.00 is 0.3413.

null

The ____ hypothesis states that there is no difference between a parameter and a specific value, or that there is no difference between two parameters.

True

The area under a normal distribution curve is always positive even if the z value is negative.

95

The area under the normal curve that lies within 2 standard deviations from the mean is __%

sampling error

The difference between a sample mean and the population mean may be referred to as ______________________.

True

The following formula can be used to find the specific value of the variable in a data set that corresponds to a particular value of the standard normal variable: X= Z*σ+μ True or False

True

The normal distribution curve can be used as a probability distribution curve for normally distributed variables. T or F

X,Y

The population correlation coefficient is computed by using all (_,_) possible pairs of data values taken from a population.

alpha

The probability of a type I error is represented by _____

positive

The range of the correlation coefficient is from -1 to +1. If there is a strong _____ linear relationship between the variables, the value of r will be close to +1.

negative

The range of the correlation coefficient is from -1 to +1. If there is a strong _____ linear relationship between the variables, the value of r will be close to -1

True

The rounding rule for a confidence interval for a proportion is to round off to three decimal places. T or F

True

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

False

The t-distribution must be used when the sample size is greater than 30 and the variable is normally or approximately normally distributed. T or F

False

When computing a confidence interval for a population mean using raw data, round off to two more decimal places than the number of decimal places in the original data. T or F

bimodal

Which of the following characteristics does not apply to a theoretical normal distribution?

bell

___ curve is another term that can be used to describe a normal distribution

Regression

__________ is a statistical method used to describe the nature of the relationship between variables.

68

one standard deviation of the mean is approximately __%

99.7

three standard deviations of the mean is approximately __._%