stats final: 1

How would you find the mean of data in the range A1 to A6 in Excel?

= AVERAGE(A1:A6)

A zookeeper takes a sample of 50 penguins and finds their average weight to be 51 lb with a standard deviation of 4 lb. How would you find a z-score corresponding to a penguin that weighs 52 lb in Excel?

=(52-51)/4

Using Excel, how would you find the standard deviation for a sample of student's GPAs located in cells B1 to B10 ?

=ST.DEV.S(B1:B10)

A geographer randomly selects twenty points in a county to study the elevation. One point is on a large hill while the other points are near water level. What is the shape of the distribution? A. Skewed right B. Skewed left C. Symmetric

A

A psychologist wants to study whether there is a correlation between sleep deprivation and the diagnosis of ADD in students. She randomly selects 20 students who are diagnosed with ADD and times how long they are asleep. She found the students slept, on average, six hours a night. What is the population? a. Students diagnosed with ADD b. The students studied who didn't get enough sleep c. Everyone with sleep deprivation d. The 20 students studied e. The average of six hours f. Students g. Everyone with ADD

A

A psychologist wants to study whether there is a correlation between sleep deprivation and the diagnosis of ADD in students. She randomly selects 20 students who are diagnosed with ADD and times how long they are asleep. She found the students slept, on average, six hours a night. What is the sample? A. The 20 students studied B. Students diagnosed with ADD C. Everyone with ADD D. Everyone with sleep deprivation E. Students F. The students studied who didn't get enough sleep G. The average of six hours

A

A researcher wants to determine the average income of the employed people of Omaha, Nebraska. He found that there are 385,600 employed people in the state. A group of 1,200 people are selected randomly to ascertain the income of each of those individuals. He finds that the average income of those 1,200 numbers to be $42,827. Identify the population in this context. A. 385,600 employed people in Omaha B. 1,200 people selected for the study C. Average income of $42,827 D. 385,600 - 1,200 constitute the population E. 385,600 + 1,200 constitute the population

A

An observation that is radically different from the rest is called A. an outlier B. the median C. the mode D. the mean E. the variance F. a variant

A

When is the mode most useful? A. Categorical data B. Numerical data C. Never D. Numerical data when significant outliers are present

A

Which of the following statistics is least impacted by outliers? A. Median B. Range C. Mean D. Variance E. Mode

A

A mechanic is interested in when transmissions fail. She randomly selects eleven cars whose transmissions have failed. Ten of them had their transmissions fail between 150,000 to 200,000 miles. The single Chevy Spark examined, however, had its transmission fail at 10,000 miles. How will the mean compare to the median? A. Impossible to tell without further information B. Mean < Median C. Mean > Median D. Mean = Median

B

The Department of Education wishes to estimate the proportion of all college students who have a job off-campus. It surveyed 1600 randomly selected students 451 had such jobs. The population of interest to the Department of Education is: A. all college students B. all college students who have a job off campus. C. all 1600 students surveyed. D. the 451 students in the survey who have off-campus jobs. E. none of these answers.

B

The difference between the maximum and minimum value is called the A. set length B. range C. standard deviation D. variance E. median

B

The score made by a particular student on a national standardized exam is the 65th percentile. This means that A. About 65% of all scores on the exam were higher than his. B. About 65% of all scores on the exam were lower than his. C. No answer text provided. D. His score is 65% of the average score. E. His score is the 65th best on the exam. F. He got about 65% of the answers correct.

B

A cop measures the speeds of drivers on a highway. The average speed is 70 mph. However, a truck is struggling to go uphill and is driving 50 mph. What can the cop say about their z-score? A. It is positive. B. It is between 0 and 1. C. It is negative. D. Not enough information. E. It is 70 mph.

C

A professor wants to study the GPAs of students enrolled in all STAT 1222 classes at her university. She asks 15 randomly selected STAT 1222 students what their GPA is and finds the average is 3.65. What is the population? A. All STAT 1222 students anywhere B. Students enrolled at her university C. All students enrolled in STAT D. 1222 classes at her university E. The 15 randomly selected students

C

Assume that the resting pulse rate for healthy adults follow a normal distribution with a mean of 69 beats per minute and a standard deviation of 9.5 beats per minute. Adam is told that the z-score of his pulse rate is -0.5. How should this statement be interpreted? A. Exactly 5% of healthy adults have pulse rates less than Adam's pulse rate. B. Adam's pulse rate is about one half of a standard deviation above average. C. Adam's pulse rate is about one half of a standard deviation below average. D. Adam's pulse rate is above the mean. E. Adam should see a doctor because his pulse rate is unusually low.

C

Seven footprints were found at a crime scene. Their length was measured in inches and recorded in the table below: 9.25, 9.25, 9.4, 9.5, 9.6, 9.6, 9.6. If another footprint was found that was 9.3 in, what would happen to the median? A. It would decrease. B. It would increase. C. It wouldn't change. D. Impossible to tell without further information.

C

A geographer randomly selects twenty points in a county to study the elevation. One point is on a large hill while the other points are near water level. How does the mean compare to the median? A. Mean = Median B. Mean < Median C. Impossible to tell without further information D. Mean > Median

D

All of the following are measures of central tendency EXCEPT: A. median B. mean C. mode D. standard deviation

D

The square root of the (a) is called the (b) A. standard deviation, variance B. mean, median C. median, mean D. variance, standard deviation

D

What is the z-score of a person whose LDL is one standard deviation above the mean? A. 90% B. 10% C. -1.0 D. 1.0 E. 10

D

Which of the following would NOT be an appropriate measure of central tendency when looking at incomes of a middle class neighborhood when one neighbor just sold their startup idea to Facebook for $1,000,000? A. Median B. Mode C. No other answer choice was an acceptable measure of central tendency D. Mean E. All other answer choices are acceptable measures of central tendency

D

A researcher wishes to estimate the average amount spent per person by visitors to a theme park. She takes a random sample of forty visitors and obtains an average of $28 per person. The population of interest is A. the amount of money spent per person. B. the forty selected visitors. C. theme park researchers. D. $28 per person. E. visitors to the theme park

E

The 54th percentile in a large data set is 98.6. Approximately what percentage of the observations are greater than 98.6? A. 98.6% B. 50% C, 1.4% D. 54% E. 46%

E

The mean score on a standardized math exam is 72.6 the standard deviation is 10.5. Paul is told that the z-score of his exam score is 1.2. Is Paul's score above average or below average?

above average

A university wants to find out how undergraduate students feel about on-campus food sources. They randomly select 10 Freshmen, 10 Sophomores, 10 Junior, and 10 Seniors to fill out a survey. This is an example of _____ sampling.

cluster sampling

Two students want to know how many parties people at their university attend per month. They ask 10 people that are in their statistics class how many parties they attend. This is an example of _____ sampling.

convenience sampling

True or false?: Median and average are the same thing?

false

Is temperature in degrees Celsius nominal, ordinal, interval, or ratio?

interval

What level of measurement is temperature?

interval

The graph is skewed left and therefore we expect that the mean is _____ than the median.

lower than

Is religious preference nominal, ordinal, interval or ratio?

nominal

What level of measurement is hair color?

nominal

Is college class ranking nominal, ordinal, interval, or ratio?

ordinal

What level of measurement is a military rank?

ordinal

Managers at a hospital are interested in the length of stay (in days) of open-heart patients who underwent surgery within the last year. Thirty five open-heart surgery patients admitted to the hospital within the last year are selected. Identify the population, sample, parameter, statistic, and variable in this problem.:average length of stay of all open-heart patients who underwent surgery in the last year.

parameter

Managers at a hospital are interested in the length of stay (in days) of open-heart patients who underwent surgery within the last year. Thirty five open-heart surgery patients admitted to the hospital within the last year are selected. Identify the population, sample, parameter, statistic, and variable in this problem.: all open-heart patients who underwent surgery in the last year.

population

Identify the following measure as either quantitative or qualitative: The genders of the first 40 newborns in a hospital one year.

qualitative

Identify the following as either qualitative, quantitative discrete, or quantitative continuous: Body temperatures in oC

quantitative continuous

Identify the following measure as either quantitative or qualitative: The 30 high-temperature readings of the last 30 days.

quantitative continuous

Identify the following measure as either quantitative or qualitative: The age (in years) of 20 randomly selected fashion model.

quantitative discrete

Identify the the following as either qualitative, quantitative discrete, or qualitative continuous: number of students responding to a survey about their names.

quantitative discrete

Is weight in lb nominal, ordinal, interval or ratio?

ratio

What level of rank is distance?

ratio

Which of the following is the symbol for sample standard deviation?

s

Managers at a hospital are interested in the length of stay (in days) of open-heart patients who underwent surgery within the last year. Thirty five open-heart surgery patients admitted to the hospital within the last year are selected. Identify the population, sample, parameter, statistic, and variable in this problem.: thirty five open-heart patients who underwent surgery in the last year.

sample

A student organization has 55 members. A table of random numbers is used to select a sample of 5. This is an example of _____ sampling.

simple random sampling

Managers at a hospital are interested in the length of stay (in days) of open-heart patients who underwent surgery within the last year. Thirty five open-heart surgery patients admitted to the hospital within the last year are selected. Identify the population, sample, parameter, statistic, and variable in this problem.: average length of stay of the thirty five selected open-heart patients.

statistic

There are 7 sections of an introductory statistics course. A random sample of 3 sections is chosen, and all students in those sections are asked to fill out an evaluation of the text book. This is an example of _____ sampling.

stratified sampling

The mathematics department wants to know how many hours a week students spend studying for math classes. They take the full list of students enrolled in math classes, and choose every 25th student from the list. This is an example of _____ sampling.

systemic sampling

The graph is symmetric and therefore we expect that the mean is _____ than the median.

the same as

Managers at a hospital are interested in the length of stay (in days) of open-heart patients who underwent surgery within the last year. Thirty five open-heart surgery patients admitted to the hospital within the last year are selected. Identify the population, sample, parameter, statistic, and variable in this problem.: length of hospital stay.

variable

What is the symbol for sample mean?

x̅

What is the symbol for population mean?

μ

Which is the symbol for population standard deviation?

σ

What is the symbol for population variance?

σ2