thanks for making me make a quizlet during summer elizabeth :)

a bin contains 72 light bulbs of which 10 are defective. if 5 light bulbs are randomly selected from the bin with replacement, find the probability that all the bulbs selected are good ones. round to the nearest thousandth

0.473

the table below describes the smoking habits of a group of asthma sufferers. if one of the 1064 people is randomly selected, find the probability that the person is a man or a heavy smoker

0.545

a manufacturer records the number of errors each work station makes during the week. the data are as follows. 6 3 2 3 5 2 0 2 5 4 2 0 1

0: 2 1:1 2: 3 3: 2 4:2 5: 2 6:1

scores on a test have a mean of 74 and a standard deviation of 12. michelle has a score of 50. convert michelle's score to a z-score

-2

a body temperature of 96.5ºF given that human body temperatures have a mean of 98.20ºF and a standard deviation of 0.62º

-2.7; unusual

a sample of 4 different calculators is randomly selected without replacement from a group containing 48 that are defective and 20 that have no defects. what is the probability that all four of the calculators selected are defective?

0.2389

the probability that luis will pass his statistics test is 0.67. find the probability that he will fail his statistics test

0.33

in a poll, respondents were asked whether they had ever been in a car accident. 353 respondents indicated that they had been in a car accident and 499 respondents said that they had not been in a car accident. if one of these respondents is randomly selected, what is the probability of getting someone who has been in a car accident? round to the nearest thousandth, if necessary

0.414

find the odds against correctly guessing the answer to a multiple choice question with 3 possible answers

2 : 1

construct a box plot for the given data. include values of the 5-number summary in all boxplots. the test scores of 40 students are listed below. 25 35 43 44 47 48 54 55 56 57 59 62 63 65 66 68 69 69 71 72 72 73 74 76 77 77 78 79 80 81 81 82 83 85 89 92 93 94 97 98

25- 98 the box is around 58 and 81 and a line in the middle on 72

find the mode(s) for the given sample data 20 36 46 36 49 36 49

36

use the data to create a stemplot. the midterm test scores for the seventh-period typing class are listed below 85 77 93 91 74 65 68 97 88 59 74 83 85 72 63 79

5 | 9 6 | 358 7 | 24479 8 | 3558 9 | 137

the annual snowfall in a town has a mean of 39 inches and a standard deviation of 10 inches. last year there were 64 inches of snow. how many standard deviations from (above or below) the mean is that?

64 inches of snow is 2.5 standard deviations above the mean

the systolic blood pressure of 18-year-old women is normally distributed with a mean of 120 mmHg and a standard deviation of 12 mmHg. what percentage of 18-year-old women have a systolic blood pressure between 96 mmHg and 144 mmHg?

68% 1 standard, 95% 2 SD, 99.7% 3 SD so, since the percentages are two standard deviations from the mean of 120, that means 96 mmHg and 144 mmHg have a percentage of 95%, according to the empirical rule

a nurse measured the blood pressure of each person who visited her clinic. following is a relative-frequency histogram for the systolic blood pressure readings for those people aged between 25 and 40. the blood pressure readings were given to the nearest whole number. approximately what percentage of the people aged 25-40 had a systolic blood pressure reading between 110 and 139 inclusive?

75%

the frequency distribution below summarizes the home sale prices in the city of Summerhill for the month of June. find the class boundaries for class 80.0-110.9

79.95, 110.95

human body temperatures have a mean of 98.20ºF and a standard deviation of 0.62º. sally's temperature can be described by z= 1.4. what is her temperature? round to the nearest hundredth

99.07ºF

refer to the table which summarizes the results of testing for a certain disease(chart). if one of the results is randomly selected, what is the probability that it is a false negative (test indicates the person does not have the disease when in fact they do)? what does this probability suggest about the accuracy of the test

P(F-T)/total= P(6)/315= 0.019 while the probability of the test being inaccurate is very small, it is still significant because people with the disease can test negative, which raises concern to healthy subjects

which is better, a score of 92 on a test with a mean of 71 and a standard deviation of 15, or a score of 688 on a test with a mean of 493 and a standard deviation of 150?

Test 1 has a higher relative position of 1.4. it is closer to a positive score of 2 above the mean, resulting in a higher test grade

explain in your own words why a bar graph can be misleading if one or both of the scales begin at some value other than zero

a bar graph can be misleading when one or both the scales don't begin at zero because it can distort the data to look more extreme. a bar could seem to be twice as big or more compared to the other bar, to emphasize an exaggerated gap between measurements. when in reality, the data is just zoomed in to make it seem there is a gap between data that actually isn't as severe if the scale began at zero

define parameter

a numerical measurement describing some characteristic of a population

define statistic

a numerical measurement describing some characteristic of a sample

the textbook defines unusual values as those data points with z scores less than z= -2.00 or z scores greater than z=2.00. comment on this definition with respect to Chebyshev's theorem; refers specifically to the percent of scores which would be defined as unusual according to Chebyshev's theorem

according to Chebyshev's theorem, at least 75% of the data lies in the interval -2 ≤ z ≤ 2. so, these values would be considered usual. hence at most 25% of the data values will be more than two standard deviations below the mean (z < -2) or more than two standard deviations above the mean (z < 2), and therefore be defined as unusual

if the standard deviation of a set of data is zero, what can you conclude about the set of values

all values are identical

the customer service department of a phone company is experimenting with two different systems. on monday, they try the first system which is based on an automated menu system. on tuesday, they try the second system in which each caller is immediately connected with a live agent. a quality control manager selects a sample of seven calls each day. he records the time for each customer to have his or her question answered. the times in minutes are listed below automated menu: 11.1, 7.4, 3.8, 2.9, 9.2, 6.3, 5.5 live agent: 6.6, 2.7, 4.1, 3.4, 5.2, 3.7

automated menu: 43.9% live agent: 30.2% there is substantially more variation in the times for the automated menu system

find the mean and median for each of the two samples, then compare the two sets of results. a comparison is made between summer electric bills of those who have central air and those who have window units. graph shown

central electric bills: mean= 66.2, median= 65 window electric bills: 71.6, median= 84 the window electric bills have higher mean and median of prices. thus, suggesting that with central air conditioner you could save more money. the difference in means is 5.4, which is high amount

determine whether the given value is from a discrete or continuous data set. the height of a 2-year-old maple tree is 28.3 ft

continuous

determine whether the given value is from a discrete or continuous data set. the temperature of a cup of coffee is 67.3ºF

continuous

define continuous and discrete data

continuous: when the measurements are not countable and have an infinite amount of solutions discrete: when the measurements are countable and have a finite amount of answers/solutions

identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience. to avoid working late, a quality control analyst simply inspects the first 100 items produced in a day

convenience

define disjoint events and undependent events

disjoint events: cannot occur at the same time independent events: the occurrence of one even does not affect the probability of occurrence of the other event

a car dealer is deciding what kind of vehicles he should order from the factory. he looks at his sales report for the preceding period. choose the vertical scale so that the relative frequencies are represented vehicle: economy, sports, family, luxury, truck sales: 30, 7.5, 52.5, 15, 45

family: 0.35 truck: 0.3 economy: 0.2 luxury: 0.1 sports: 0.5

lori asked 24 students how many hours they had spent doing homework during the previous week. the results are shown below. 11, 10 , 11, 8, 11, 11, 15, 13, 11, 8, 13, 10, 10, 13, 11, 10, 13, 11, 10, 13, 10, 13, 13, 8 construct a frequency distribution. use 4 classes, a class width of 2 hours, and a lower limit of 8 for the first class

hours: 8-9.9, 10-11.9, 12-13.9, 14-15.9 frequency: 3, 13, 7, 1

is it "unusual" to get 5 when a pair of dice is rolled?

no

define observational study and an experiment

observational study: observing and measuring specific characteristics without attempting to modify the subjects being studied experiment: apply some treatment and then observe its effects. subjects are called experimental units. there is a treatment(gets the treatment) and a control(does not get the treatment) group

identify the type of observational study(cross-sectional, retrospective, prospective). a researcher plans to obtain data by following those in cancer remission since january of 2005.

prospective

determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate. ages of survey respondents.

ratio

find the range, variance, and standard deviation for each of the two samples, then compare the two sets of results. when investigating times requires for drive-through service, the following results(in seconds) were obtained restaurant A: 120, 67, 89, 97, 124, 68, 72, 96 restaurant B: 115, 126, 49, 56, 98, 76, 78, 95

restaurant A: 57 sec; 493.98 sec^2; 22. 23 sec restauraunt B: 77 sec; 727.98 sec^2; 26.98 sec there is more variation in the times for restauraunt B

identify the sample and population. also, determine whether the sample is likely to be representative of the population. in a poll of 50,000 randomly selected college students, 74% answered "yes" when asked, "do you have a television in your dorm room?"

sample: 50,000 selected college students population: ALL college students the sample is a random sample and is large enough and to be representative of the population, although not all college students stay in dorms

the scores on a recent statistics tests are given in the frequency distribution below. construct the corresponding relative frequency distribution. round relative frequencies to the nearest hundredth of a percent if necessary

scores: 0-60, 61-70, 71-80, 81-90, 91-100 relative frequency: 16.13%, 32.26%, 25.81%, 19.35%, 6.45%

determine whether the given value is a statistic or a parameter. after taking the first exam, 15 of the students dropped the class

statistic

define sample

sub-collection of members of a population

identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience. a tax auditor selects every 1000th income tax return that is received

systematic

define population

the complete collection of all measurements/data that are being considered

sometimes probabilities derived by the relative frequency method differ from the probabilities expected from classical probability methods. how does the law of large numbers apply in this situation

the law of large numbers says that as a procedure is repeated again and again, the relative frequency of an event tends to approach the actual (theoretical) probability, calculated using classical probability methods

the median of a data set is always/sometimes/never (select one) one of the main data points in a set of data. explain your answer with brief examples

the median is SOMETIMES one of the data points in a set of data. this is because the median is a measure of center and when a data has an even amount of data value you must calculate the average between two middle numbers. to do this the data must be in either increasing or decreasing order ex. 1 2 3 4, the median would be 2 and 3 since they are the middle values. however, you must add them together and divide by two, getting 2.5. so, that is why the median is sometimes not one of the data points. if there were an odd number of data values, then the median would be on of the data points

a researcher investigated whether following a vegetarian diet could help to reduce blood pressure. for a sample of 85 people who follow a vegetarian diet for 4 months, the mean systolic blood pressure was 124 mmHg and for a sample of 75 people who follow a non-vegetarian diet for 4 months, the mean of systolic blood pressure was 138 mmHg. methods of statistics show that if a vegetarian diet had no effect on blood pressure, there would be less than 1 chance in a 100 of getting these results. A) does the result have statistical significance? why or why not? B) does the result have a practical significance? why or why not?

the result does have statistical significance because it is unlikely to occur by chance. the result is a lower blood pressure in the vegetarian diet group and there is a 1/100 chance of getting this result. the result does have practical significance since the difference in mean systolic blood pressures between the vegetarian and non-vegetarian group(124 mmHg versus 138 mmHg) is quite a bit. a systolic blood pressure of 124 mmHg is elevated, whereas a systolic blood pressure of 138 mmHg is high

use critical thinking to determine whether the sampling method appears to be sound or is flawed. "7 out of 10 dentist recommended Brand X toothpaste". this finding is based on the results of a survey of 10 randomly selected dentists. what is wrong with this survey?

the survey is flawed. the sample size is too small. in addition, dentists often receive a commission on sales of brands of toothpaste they promote, so the sample may be biased

a parcel delivery service lowered its prices and finds that it has delivered twice as many parcels this year as it did last year. to illustrate this fact, the manager draws a graph as shown below. each cube depicts a parcel. the side length of the "parcel" on the right is twice the side length of the "parcel" on the left. why is this graph misleading? what visual impression is created by the graph?

this is called a pictograph. pictographs are misleading because they are not drawn to scale resulting in false data. in the picture above the second block is supposed to be "tice" as big as last years. however, what happens in a pictograph when you double the length you also double the height and volume. this results in a drawing that is 8x larger than what it should be. Thus, creating a visual impression that drastically alters the true amount of measurement

find the mean of the data summarized in the given frequency distribution. the test scores of 40 students are summarized in the frequency distribution below. find the mean score. score: 50-59, 60-69, 70-79, 80-89, 90-99 students: 6, 5, 6, 11, 12

to find the mean score first you must identify the score midpoints. 50+59/2=54.5 64.5, 74.5, 84.5, 94.5 then enter both sides of data into STAT on the calculator. L1=midpoints, L2= frequencies the mean of the data is 79

construct the cumulative frequency distribution that corresponds to the given frequency distribution

weight(oz): less than 1.7, less than 2.2, less than 2.7, less than 3.2, less than 3.7 cumulative frequency: 5, 7, 12, 17, 30

an electronics store receives a shipment of eight boxes of calculators. each box contains ten calculators. a quality control inspector chooses a box by putting eight identical slips of paper numbered 1-8 into a hat, mixing thoroughly and then picking a slip at random. he then chooses a calculator at random from the box selected using a similar method with ten slips of paper in a hat. he repeats the process until he obtains a sample of 5 calculators for quality control testing. does this sampling plan result in a random sample? simple random sample? explain

yes; yes. the sample is random because all calculators have the same chance of being selected. it is a simple random sample because all samples of 5 calculators have the same chance of being selected