STATS FINAL (Multiple Choice)

if we have 3 red candies, 5 blue, 7 yellow, 12 orange, and 9 green, what is the relative frequency of the green candies? a) 0.33 b) 0.45 c) 0.25 d) 9

0.25

the percentage of measurements that are above the 39th percentile is.. a) cannot be determined b) 39% c) 71% d) 61%

61%

when we use the median as a measure center, what measure of dispersion should we use? a) Q3-Q1 b) variance c) range d) standard deviation

Q3-Q1

What is a frame? a) a frame is the sample taken from the population being studied b) a frame is a list of the individuals in the sample being studied c) a frame is a list of the population in the sample being studied d) a frame is a population being studied

a frame is a list of the population in the sample being studied

a point estimate is... a) mainly used to find average values of a statistic b) a statistic used to estimate a parameter c) any estimate of a point on the number line d) a parameter used to estimate a statistic

a statistic used to estimate a parameter

what are the requirements of a good sample? a) the sample size must be less than 5% of the population when sampling without replacement b) all answers required c) must be chosen randomly from the population d) must be representative of the population and avoid bias.

all answers required

in Washington state, the mean heating cost per month is $122 with a standard deviation of $12. if the distribution can be considered bell shape, what percentage of homes will have a monthly utility bill more than $110? a) approx. 95% b) approx. 32% c)% approx. 84 d) approx. 16%

approx. 84

what is meant by confounding?

confounding in a study occurs when the effects of two or more explanatory variables are not separated. therefore, any relation that may exist between an explanatory variable and the response variable may be due to some other variable or variables not accounted for in the study.

to estimate the rate of cell phone ownership among adults in the united states, a statistics student just uses as a sample everyone in her own apartment building to estimate the overall percentage of U.S. adults who own a cell phone. what sampling technique is used? a) cluster b) systematic c) simple random d) convenience e) stratified

convenience

I want to do a hypothesis test to see if a new teaching method is better than the one currently being used. the null hypothesis is that student success is the same as before. the alternative hypothesis is that there is improvement. what would be a type II error? a) deciding that the new method is better b) deciding that the new method is better when it is not c) a type II error cannot be committed in this situation d) deciding that the new method is not better when it is

deciding that the new method is not better when it is

Which branch of statistics deals with the organization and summarization of collected information? a) survey design b) inferential statistics c) computational statistics d) descriptive statistics

descriptive statistics

a medical researcher wants to study the relationship between exercise and weight loss in men. she recruits 100 male volunteers and randomly assigns them to two groups. Group 1 will consume 2000 calories a day and remain sedentary and group 2 will also consume 2000 calories a day but will be required to exercise 2 hours a day. this is a(n)... a) cohort study b) designed experiment c) case-control study d) observational study

designed experiment

a hypothesis test results in a p-value of 0.01. choose the correct statement. a) either the null hypothesis is true or, if it is false, a sample this extreme or more so could only occur about once out of hundred times b) the probability of mistakenly accepting a false null hypothesis is 99% c) either the null hypothesis is false or, if it is true, a sample this extreme or more so could only occur about once out of hundred times d) the probability of mistakenly accepting a false null hypothesis is 1%

either the null hypothesis is false or, if it is true, a sample this extreme or more so could only occur about once out of hundred times

what does it mean if a statistic is resistant? a) extreme values (very large or small) relative to the data do not effect its value substantially. b)changing particular data values affects its value substantially c) an estimate of its value is extremely close to its actual value d) extreme values (very large or small) relative to the data affects its value substantially.

extreme values (very large or small) relative to the data do not effect its value substantially.

data was collected to determine the distance, d, a golf ball will travel when hit by a golf club with a certain speed. the speed, s, is measured in miles per hour and the length the ball travels, d, is measured in yards. the following formula gives the relationship d=3.2+57.7s. Intemperate the slope. a) for each additional mile per hour increase in speed, the ball will travel an additional 57.7 yards b) for each aditionl 3.2 yards the ball will need to be hit 57.7 miles per hour. c) for each additional mile per hour increase in speed, the ball will travel an additional 3.2 yards d) the ball will travel 57.7 yards

for each additional mile per hour increase in speed, the ball will travel an additional 57.7 yards

which branch of statistic uses methods that take a result from a sample, extend it to the population, and measure the reliability of the result? a) descriptive statistics b) probability statistics c) inferential statistics d) sample statistics

inferential statistics

numerical summary of a population is a... a) quantity b) parameter c) variable d) statistic

parameter

as part of a study on climate change, meteorologist monitors the annual number of hurricanes in the pacific ocean. the variable is... a) quantitative and numerical b) qualitative and discrete c) quantitative and continuous d) quantitative and discrete

quantitative and discrete

when the results of a hypothesis test are determined to be statistically significant, then we _______________the null hypothesis a) fail to reject b) reject c) compartmentalize d) polarize

reject

the slope of the best fit line associated linear correlation coefficient always shares the same... a) same y-intercept b) same value c) have nothing in common d) same sign (+/-)

same sign (+/-)

assume that all the students at edmonds community college represent the population being considered. to choose a sample of 30 students I first obtain a list of all EdCC students identified by their student id numbers and then randomly choose 30 id numbers. What type of sampling was used? a) convenience b) systematic c) stratified d) simple random e) cluster

simple random

A(n) __________________is a numerical summery value for a sample a) parameter b) qualitative variable c) statistic d) quantitative descriptor

statistic

Define statistics. a) statistics is the science if manipulating, reorganizing, and editing information to produce the desired results. in addition, statistics is about providing the required answer with the desired level of confidence. b) statistics encompasses all scientific disciplines in which percentages are used, data are analyzed, and probabilities are found. In addition, statistics references any mathematical model which is reported using percentages or proportions. c) statistics is the science of collecting, organizing, summarizing, and analyzing information to draw a conclusion and answer questions. in addition, statistics is about providing a measure of confidence in any conclusions.

statistics is the science of collecting, organizing, summarizing, and analyzing information to draw a conclusion and answer questions. in addition, statistics is about providing a measure of confidence in any conclusions.

what type of sampling involves dividing the population into homogeneous subgroups and then randomly selects individuals from each subgroup in a way that cause the sample to be proportional to the population? a) simple random b) stratified c) cluster d) systematic

stratified

which type of sampling matches the proportions of the sample to the proportions of the population and therefore helps to eliminate the problem of undercoverage? a) systematic b)convenience c) stratified d) simple random e) cluster

stratified

a histogram of a set of data indicates that the distribution of the data is skewed right. which measure central tendency will likely be larger, the mean or the median? why? a) the median will likely be larger because the extreme values in the left tail tend to pull the median in the opposite direction of the tail b) the median will likely be larger because the extreme values in the right tail tend to pull the median in the direction of the tail c) the mean will likely be larger because the extreme values in the right tail tend to pull the median in the direction of the tail d) the mean will likely be larger because the extreme values in the left tail tend to pull the median in the opposite direction of the tail

the mean will likely be larger because the extreme values in the right tail tend to pull the median in the direction of the tail

what does z-score measure? a) the absolute value of the distance between the data value and the mean. b) the number of standard deviations that a data value is located above or below the mean. c) the percentage of scores below a given data value. d) the distance between two specific data values

the number of standard deviations that a data value is located above or below the mean.

what happens to the probability of making type II error, beta, as the level of significance, alpha, decreases? why? a) the probability decreases the more careful researcher is, the lower the chances of making any error b) the probability increases. the sum of alpha and beta always equals 1. c) the probability decreases. type I and type II errors are proportional d) the probability increases. type I and type II errors are inversely proportional

the probability increases. type I and type II errors are inversely proportional

According to the central limit theorem, the distribution of the parent population and the distribution of the sample mean will always share: a) the same "shape" and mean b) the same mean c) the same standard deviation d) the same "shape"

the same mean

a poll of 1200 adults in mexico found that 85% identified themselves as Catholics. the margin of error was 3 percentage points with 95% confidence. which of the following (one) represents a reasonable interpretation? a) in 95% of the samples of adults in mexico, the proportion identifying as catholic was between 82% and 88%. b) there is 95% confidence that 85% of the adults in mexico identify themselves as catholic c) there is a 95% confidence that the proportion of adults in mexico who identify themselves as catholic is between 82% and 88% d) there is between 92% and 98% confidence that 85% of the adults in mexico identify themselves as Catholics.

there is a 95% confidence that the proportion of adults in mexico who identify themselves as catholic is between 82% and 88%

what must be true if the liner correlation coefficient is exactly negative one? a) there is a perfect linear relationship between two quantitative variables and when the explanatory variable increases, the response variable decreases. b) there is no liner relationship c) there is a perfect linear relationship between two quantitative variables and when the explanatory variable decreases, the response variable decreases. d) there is less of a linear relationship than if the correlation coefficient was closer to zero.

there is a perfect linear relationship between two quantitative variables and when the explanatory variable increases, the response variable decreases.

three years ago, the mean price of a single-family home two years ago was $300,000. a real estate broker believes that the mean price has *increased* since then. suppose a hypothesis test is performed and the p-value is greater than the level of significance... which of the following is correct conclusion? a) there is sufficient evidence to conclude that the mean price of a single family has increased b) there is not sufficient evidence to conclude that the mean price of a single family has increased c) there is sufficient evidence to conclude that the mean price has remained the same d) there is sufficient evidence to conclude that the mean price has remained the same

there is not sufficient evidence to conclude that the mean price of a single family has increased

the mean price of a single-family home two years ago was $300,000. a real estate broker believes that because of improvements in the economy, the mean price has increased since then. What would be a type one error. a) a type I really couldn't occur in this situation b) thinking home prices have increased when they have remained the same c) thinking the home prices are the same as two years ago when they have actually risen d) thinking that home prices have decreased.

thinking the home prices are the same as two years ago when they have actually risen

when will t-distribution be used? a) working with hypothesis tests and small sample sizes <30 b) working with means and a fairly large sample c) working with means and sigma σ is unknown d) working with means and sigma σ is known

working with means and sigma σ is unknown