math 105 final exam
How do you find standardized score?
(observed value - mean)/standard deviation
intervals that can give you a picture of where values on any normal curve will fall
Empirical Rule
What are the parts of the five number summary?
minimum, maximum, first quartile, third quartile, median
A population of measurements that follow a normal distribution is said to be _____________-
normally distributed
The ____________ hypothesis is usually written to express the fact that nothing is happening.
null
A measure of how unlikely the test statistic would be if the null hypothesis were true is the
p value
Frequency curves are quite useful for determining what ________ of the population of measurements falls into a certain range.
proportion
Using the relative frequency approach, we can define the probability of any specific outcome as the _________ of times it occurs over the long run.
proportion
a straight line that comes as close as possible to the points in a scatterplot
regression line
If the test statistic for two variables in contingency table is 6.34, then there is a statistically __________ relationship between these two variables.
significant
what represents the number of standard deviations the observed value or score falls from the mean?
standardized score
How do you find the range of a set of data?
subtract the minimum value from the maximum value
What does proportion tell you?
the percentage of the population that falls below you.
What type of useful information tells us how spread out the data is?
variance
equation for the regression line
y=a+bx
What is another name for standardized score?
z score
The ___________ of a test for a certain disease is the proportion of people who correctly test positive when they actually have the disease
A
Using the criterion of .05, which of the following results allows a researcher to conclude that a relationship between two categorical variables is statistically significant? A) p-value= .04 B) p-value= .5 C) p-value= .95
A
which of these does not apply to a statistically significant relationship between two categorical variables? A) the relationship between two variables is very important from a practical standpoint B) the relationship observed in the sample was unlikely to have occurred unless there really is a statistically significant C)The notion that this relationship could have happened by chance is deemed to be implausible
A
What type of graph shows a picture related to a stemplot?
A histogram
What is an outlier defined as?
Any value more than 1.5X IQR beyond the closest quartile
What is the empirical rule?
68% mean plus or minus the standard deviation 95% mean plus or minus 2X the standard deviation 99.7% mean plus/minus 3X the standard deviation
Suppose there is not enough evidence to conclude that the relationship in the population is real. Which of the following is not an equivalent way of saying this? A) the relationship is not statistically significant B) we accept the null hypothesis C) we cannot reject the null hypothesis
B
Suppose you know that for each ticket the probability of winning a certain instant win lottery game is 1/100. You have purchased 99 tickets so far, with no luck. What is your chance that the next ticket you buy is a winner? A) 99/100 B) 1/100 C) 100%
B
Which of the following statements is not true about the chi square statistic for a 2x2 contingency table? A) If it is greater than 3.84, reject the null hypothesis and accept the alternative hypothesis. B) 95% of the tables for sample data from populations in which there is no relationship will have a chi square statistic of 3.84 or greater. C) If it is greater than 3.84, the relationship in the table is considered to be statistically significant
B
Let the population contain 60% Republicans and 40% democrats. Suppose numerous random samples of size 1,000 are taken from this population. The proportions of democrats from the various samples of size 1,000 will have what approximate standard deviation. A) .24 or 24% B) .00024 or .024% C) .015 or 1.5% D) .49 or 49%
C
Which of the following chances can be quantified exactly? A) the chance that it will rain tomorrow B)the chance that you will live to be 100 C) the chance of getting four of a kind in a poker hand
C
Which of the following statements is true about chi square tests? A) a large chi square statistic results in a large p value B) A large p value means that there Is a good chance that the relationship is statistically significant C) If the two variables are not related in the population, then less than 5% of the samples you could ever take would give you a test statistic of 3.84 or larger.
C
If the data is skewed to the left, what side do most of the values lie on?
The right side
How do you calculate the interquartile range?
You subtract Q1 from Q3
What type of plot is an easy way to put a list of numbers in order while getting a picture of their shape?
a stemplot
If two events are mutually exclusive, they _______ be independent
cannot
A ________ test is a statistical procedure that is used to determine whether or not there is a relationship between two categorical variables.
chi- square
an indicator of how closely their values fall to a straight line on a scatterplot
correlation
The expected value ________ have to be one of the possible outcomes
does not
The ___________ represents the average value of any measurement over the long run.
expected value
The most common type of picture for a population is a _________
frequency curve
