Honors Statistics Exam

The following is a histogram showing the actual frequency of the closing prices of a particular stock on the New York Stock Exchange over a 50 day period. The class that contains the third quartile is

30-40

Researchers looking at the relationship between the type of college attended (public or private) and achievement gather the following data on 3265 people who graduated from college in the same year. The "management level" describes their job description 20 years after graduating from college. How many people are in this survey?

3265

The veterinary bills for dogs at the SPCA are summarized in the ogive shown. Estimate the IQR of these expenses.

$100

The Model United Nations club at your school consists of 4 juniors and 8 seniors. Four students will be chosen at random to represent the school at a state conference. What is the probability that the students chosen will consist of 1 junior and 3 seniors?

0.45

The area under the standard Normal curve corresponding to -0.3<z<1.6 is

0.5631

The average height of women between the ages 30-39 is 163.2 cm with a standard deviation of 9.3 cm. Find the probability that a woman in this age group is over 160 cm if it is known that the distribution is approximately normal.

0.6346

Which data set has a median of 7 and a mode of 8?

1,2,6,8,8,9

At the start of the school year, a high school teacher asks every student in her classes to fill out a survey that asks for their age, gender, the number of years they have lived at their current address, their favorite school subject, and whether they plan to go to college after high school. Which of the following best describes the variables that are being measured?

3 categorical and 2 quantitative variables

Use the spinner below to answer the question. Assume that it is equally probable that the pointer will land on any one of the five numbered spaces. If the pointer lands on a borderline, spin again. Find the probability that the arrow will land on an odd number.

3/5

The British Medical Journal published an article on December 10, 2014, entitled "The Association between Exaggeration in Health Related Science News and Academic Press Releases: Retrospective Observational Study." Among other findings, they reported that 36% of the press releases contained exaggerated connections between animal research results and conclusions about similar effects in humans. What is the sample?

462 press releases on biomedical and health science

In a Normal model, approximately what percent of observations have values that are more than two standard deviations from the mean?

5%

A fair coin has come up "heads" 10 times in a row. The probability that the coin will come up heads on the next flip is

50%

Researchers looking at the relationship between the type of college attended (public or private) and achievement gather the following data on 3265 people who graduated from college in the same year. The "management level" describes their job description 20 years after graduating from college. What percent of those who attended a private are at a medium management level?

53.1%

Researchers looking at the relationship between the type of college attended (public or private) and achievement gather the following data on 3265 people who graduated from college in the same year. The "management level" describes their job description 20 years after graduating from college. What percent of those surveyed attended a public college?

54.2%

The cumulative relative frequency graph at the right show the distribution of lengths in centimeters of fingerlings at a fish hatchery. The 50th percentile for this data is

6.1cm

If SAT scores are normally distributed with a mean of 500 and a standard deviation of 100, what minimum score is needed to ensure that you are in the top 7%?

648

In a Normal model, what percent of observations are expected to be between one standard deviation from the mean?

68%

A medical researcher collects health data on many women in each of several countries. The following list gives the five-number summary for the weights of adult women in one of the countries. About what percent of Country A women weigh between 110 and 240 pounds?

75%

In a Normal model, approximately what percent of observations have values that are equal to or greater than one standard deviation below the mean value?

84%

Two sections of a class took the same quiz. Section A had 15 students who had a mean score of 80, and Section B had 20 students who had a mean score of 90. Overall, what was the approximate mean score for all of the students on the quiz?

85.7

For the histogram below, what is the proper ordering of the mean and median? Note that the graph is NOT numerically precise-only the relative positions are important

II is the mean and III is the median

Why is a sample used more often than a population?

It is usually impossible to count the entire population

A probability experiment is conducted in which the sample space of the experiment is S=(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15). Let the even A=(6,7,8,9) and event B=(8,9,10,11,12). Assume that each outcome is equally likely. List the outcomes in A and B. Are A and B mutually exclusive?

No (8,9)

The principal of a small elementary school wants to select random sample of 24 students. The school has 12 classrooms with 18 students in each class. She decides to randomly select two students from each classroom. Is this a simple random sample?

No, because not all combinations of 24 students could have been chosen

To check the effect of cold temperatures on the battery's ability to start a car, researchers purchased a battery from Sears and one from NAPA. They disabled a car so it would not start, put the car in a warm garage, and installed the Sears battery. They tried to start the car repeatedly, keeping track of the total time that elapsed before the battery could no longer turn the engine over. Then they moved the car outdoors where the temperature was below zero. After the car had chilled there for several hours, the researchers installed the NAPA battery and repeated the test. Is this a good experimental design?

No, because temperature is confounded by brand

A school district administrator sent a survey to all teachers in the district. Only 30% of the teachers responded to the survey. Which of the following bias is true?

Non-response bias

Which best describes the distribution of the histogram?

Normal

Give a description of the distribution seen in this histogram.

Right Skewed

Which of the following is an example of an experiment?

Similar patients with high blood pressure are randomly given three different doses of a new drug and their blood pressure is observed.

To test the effects of a new fertilizer, 100 plots were used and each was divided in half. Fertilizer A is randomly applied to one half of each plot, and B to the other. This is

a matched pairs experiment

The purpose of doing an experiment is to

determine cause and effect

In an experiment, the evaluators and the participants do not know which treatment group the participants are in. This is called

double-blinding

Each month interviewers visit about 53,000 of the 99 million households in the region and question the occupants over 14 years of age about their employment status. Their responses enable the interviewers to estimate the percentage of people in the labor force who are unemployed. What is the response variable?

employment status

The probability that event A will occur is P(A)= number of successful outcomes/ number of unsuccessful outcomes

false

School administrators collect data on students attending the school. Which of the following variables is quantitative?

grade point average

Suppose that the viscosity (measured in pascal-seconds) of a fluid used in a chemical process follows a Normal model. A sample of that fluid has a z-score of 1.77. This means that this sample

has a viscosity that is 1.77 standard deviations higher than the average sample

Placebos are a tool for

control

Twenty dogs and twenty cats were subjects in an experiment to test the effectiveness of a new flea control chemical. Ten of the dogs were randomly assigned to an experimental group that wore a collar containing the chemical, while the others wore a similar collar without the chemical. The same was done with the cats. After 30 days veterinarians were asked to inspect the animals for fleas and evidence of fleabites. The experiment is

randomized block, blocked by species

Compares the extreme values of the data

range

The shift manager at a manufacturing plant calls each of the employees into his office and asks them a series of questions about job satisfaction. This method of polling is most likely to result in what type of bias?

response bias

A company sponsoring a new Internet search engine wants to collect data on the ease of using it. Which is the best way to collect data on ease of use?

sample survey

Summarizes how far each data value is from the average of the data

standard deviation

Mrs. Scott randomly selected 10 of her 72 Algebra 2 exams to grade and found that he average score for these was 81%. 81% is a

statistic

Which of the following situations involves a permutation?

students are assigned seats in study hall, a bank customer chooses a new ATM code, a survey asks respondents to rank political candidates in order of preference, every summer the school custodian changes the locker combinations

Each month interviewers visit about 53,000 of the 99 million households in the region and question the occupants over 14 years of age about their employment status. Their responses enable the interviewers to estimate the percentage of people in the labor force who are unemployed. What is the sample?

the 53,000 households visited in the region

The interquartile range describes

the middle 50% of the data

Which of the following symbols is used for the mean of the sample?

x bar

Which of the following is the correct z-score and description for an observation of 12 ft that comes from a data set with a mean of 21.2ft and a standard deviation of 4ft.

z=-2.3, The data is an outlier and is 2.3 standard deviations from the mean.

A serial number on an implanted medical device consists of 3 letters followed by 4 digits. The first number cannot be zero. How many serial numbers are possible?

158,184,000

A physics exam consists of nine multiple choice questions and six open ended problems in which all work must be shown. If an examinee must answer six of the multiple choice questions and three of the open ended problems, in how many ways can the questions and problems be chosen?

1680

A sandwich shop offers a lunchtime meal combo, consisting of a sandwich, a side dish, and a drink. You can choose from turkey, ham, or veggie sandwiches, potato chips or salad as a side dish, and coffee, soda, or iced tea to drink. How many different lunch combos are possible?

18

A couple plans on having children. How many outcomes are possible?

2

Researchers looking at the relationship between the type of college attended (public or private) and achievement gather the following data on 3265 people who graduated from college in the same year. The "management level" describes their job description 20 years after graduating from college. What percent of those surveyed attended a public college and are at a high management level?

2.3%

A church has 7 bells in its bell tower. Before each church 5 bells are rung in sequence. No bell is rung more than once. How many sequences are there?

2520

How is a sample related to population?

A sample is a representative subset of a population

Your stats teacher tells you your test score was the 3rd quartile for the class. Which is true?

About 25% of your classmates got a score that was higher than your score

Describe the shape of the histogram

Bimodal

The mode is a measure of center most likely to be affected by an outlier.

False. The mean is the measure of center most likely to be affected by an outlier.

Splits a histogram into halves.

Median

Which of the following is not helpful when looking at the distribution of data?

Pie Graph

The lifetime of a smartphone battery while playing a video is described by a Normal model. If 95% of batteries last between 8.5 and 11.5 hours, what are the mean and standard deviation of the deviation of the distribution of battery lifetimes while playing videos?

The mean is 10 hours and the standard deviation is 0.75 hours.

In a medical experiment, half of the patients will receive the conventional treatment, and half of the patients will receive the new treatment. Which of the following is a correct way to determine which patients get which treatment?

The patients will be assigned numbers, and half of the numbers will be randomly chosen, without replacement, to be given the new treatment. Patients not getting the new treatment will get the conventional treatment.

Which of these is an advantage of using a stratified sample instead of a simple random sample?

The stratified random sample allows you to get information about each stratum

The graph below shows how mothers of young children respond to the question, "How many times a week fo you choose fast food as a dining option for your family?"

Using proportionally-sized hamburgers exaggerates differences between responses

Each month interviewers visit about 53,000 of the 99 million households in the region and question the occupants over 14 years of age about their employment status. Their responses enable the interviewers to estimate the percentage of people in the labor force who are unemployed. What is the population?

all people in the region who are 14 years old

Which of the following situations is probably not truly random?

asking a friend to pick a number between 1 and 10

A researcher observes that, on average, the number of divorces in cities with Major League Baseball teams is larger than in cities without Major League Baseball teams. The most plausible explanation for this observed association is that the

association is due to the presence of a lurking variable

Which of the following is not required in an experimental design?

blocking

If we want to discuss any gaps and clusters in a data set, which of the following should not be chosen to display the data set?

boxplot

Which type of plot would be least likely to reveal that a distribution is bimodal?

boxplot

A school district administrator sent a survey to all teachers in the district. Only 30% of the teachers responded to the survey. How was the data collected?

census

The local chapter of the National Honor Society offers after school tutoring, but the sessions are not well attended. Hoping to increase attendance, the tutors design a survey to gauge student intrest in times, locations, and days of the week that students could attend tutoring sessions. They choose 3 English classes at random, and have all of the students in each class take the survey. What type of sample is this?

cluster random sample

A maple sugar manufacturer wants to estimate the average trunk diameter of Sugar Maples trees in a large forest. There are too many trees to list them all and take a SRS, so he divides the forest into several hundred 10 meter by 10 meter plots at random, and measures the diameter of every Sugar Maple in each one. This is an example of a

cluster sample

For data that is skewed, which measures of center and spread would be most appropriate to use

median and IQR

A set of data is roughly symmetric and bimodal. Which of the following must be true?

median=mean

The United States Census collects data in many variables about individuals and households. Which variable is categorical?

type of residence

Statistically significant results are

unlikely to occur simply by chance.

Which of the following symbols is used for the mean of the population?

upside down n

Which of the following is a conditional distribution?

what percent are low level management who attended a private college