Intro Stats Final Exam Review

At one college, GPA's have a distribution thatt is unimodal and symmetric with a mean of 2.6 and a standard deviation of 0.5. What is the range of GPA's from one standard deviation below the mean to one standard deviation above to mean?

0.5 to 3.1

A store manager kept track of the number of newspapers sold each week over a seven-week period. The results are shown below. 58, 48, 223, 156, 289, 248, 238 Find the median

223 newspapers

The mean age of lead actresses from the top ten grossing movies of 2010 was 29.6 years with a standard deviation of 6.35 years. Assume the distribution of the actrsses' ages is approximately unimodal and symmetric. Between what two values would you expect to find about 68% of the lead actresses ages?

23.25 and 35.95 years

A statistics student collected data from other students in her class who ride a bike to school. The following table shows data about their bikes. Color, series number, weight, road bike, average speed How many variables are there?

5

The national center for health statistics has found that there is a 5.01% chance than an American citizen will die from an accident. What is the probability that you will not die from an accident?

94.99%

A large state university conducted a survey among their students and received 400 responses. The survey asked the students to provide the following information: -Age -Year in school -Major What type of graph would you use to describe the variable major?

A bar chart because major is a categorical variable

Which of the following statements regarding the correlation coefficient is true?

A correlation coefficient of -1 means that as one variable increases, the other decreases

A large state university conducted a survey among their students and received 300 responses. The survey asked the students to provide the following information: -Age -Year in school -Gender -GPA What type of graph would you use to describe the variable age?

A histogram because age is a numerical variable

What is the difference between a histogram and a relative frequency histogram?

A histogram uses counts to record how many observations are in a date set, and a relative histogram uses proportions

Which of the following statements regarding the correlation coefficient is not true?

A value of 0.00 indicates that two variables are perfectly linearly correlated

Which of the following is not a true statement about the CLT for sample means?

All of these statements are true about the CLT for sample means

In a recent school poll, the administrators asked if students were satisfied with the school's course offerings. What is the population of interest here?

All students who attend the school

The null hypothesis is ? to be ? and is only rejected when the observed outcome is shown to be ? .

Assumed; true; extremely unlikely

Marital status of each member of a randomly selected group of adults is an example of what type of variable?

Categorical variable

A group of students is divided into two groups. One group is a given a new chewable vitamin and the other group is given a placebo. After six months they are asked to fill out a questionnaire and given a health exam to see whether the new vitamin has health benefits that are better than a placebo. Is this controlled or observational?

Controlled

Suppose it has been established that "annual income and "years of college" are linearly related, and that the relationship can be modeled using the following equation: ? variable, and "years of college" is the ?variable. The two variables have a ? linear relationship.

Dependent, independent, positive

Determine whether the variable would best be modeled as continuous or discrete: The number of cups dispensed from a beverage vending machine during a 24-hour period.

Discrete

Is the following an example of theoretical probability or empirical probability? A homeowner notes that five out of seven days the newspaper arrives before 5 pm. He concludes that the probability that the newspaper will arrive before 5 pm tomorrow is about 71%.

Empirical

A class of 30 introductory statistics students took a quiz worth 100 points. The standard deviation of the scores was 0. What must be true about the sutdents' scores?

Every student received the same score

Which of the following statements is true about the t-distribution?

For large sample sizes, the t-distribution has the same properties as the normal curve

When constructing a confidence interval, if the level of confidence increases the margin of error will ? and the confidence interval will be ? . A lerger sample size will improve the accuracy of the confidence interval, therefore margin of error will ? and the confidence interval will be ? .

Increase, wider,. Decrease, narrower.2

Classify the events as independent or not independent: Events A and B where the probability of event A occurring is 0.3, the probability of event B occurring is 0.3, and the probability of both event occurring is 0.09.

Independent

What generally happens to the sampling error as the sample size is decreased?

It gets larger

Which of the following statements about bar graphs is true?

It is appropriate to have gaps between the bars on the graph, it sometimes doesn't matter in which order you place the bars representing different categories, on a bar graph the width of the bars has no meaning.

Which of the following is not true about the alternative hypothesis?

It is assumed to be true

Which of the following statements is true about the confidence interval for a population proportion?

It is equal to the sample proportion plus or minus a calculated amount called the margin of error

Which of the following is not one of the four steps of the hypothesis test?

Make a decision to either acdcpt the null hypothesis or accept the alternative hypothesis

Which scatterplot shows a greater strength of association between the variables>

More dots and wider = stronger

Near zero trend

No significant upward or downward trend

The average gas mileage of the top selling mini-vans for each U.S car manufacturer is an example of what type of variable?

Numerical variable

"People with diabetes are at higher risk for certain cancers than those without the blood sugar, disease, suggests a new study based on a telephone survey of nearly 400,000 adults." Is this controlled or observational?

Observational study

What does it mean when we say that the sample mean is unbiased when estimating the population mean?

On average, the sample mean is the same as the population mean.

Suppose that the age of all the US first ladies when they married was recorded. The mean age of US first ladies when they married would be a ?

Parameter

The collection of the ages of all the US first ladies when they married is a ?

Parameter

Researchers are interested in learning more about the age of women when they marry for the first time so they survey 500 married of divorced women and ask them how old they were when they first married. The collection of the ages of the 500 women when they first married is a ....

Sample

Suppose the process of taking random sample of size 30 is repeated 200 times and a histogram of the 200 sample means is created. Would the histogram be an approximate display of the population distribution, the distribution of a sample, or the sampling distribution of means?

Sampling distribution of means

Researchers are interested in learning more about the age of men when they marry for the first time so they survey 500 married or divorced men and ask them how old they were when they first married. The mean age of the 500 men when they married for the first time would be a ?

Statistic

Suppose temperatures and monthly ice cream sales were meausred for 100 randomly selected cities. Which variable is the explanatory variable and which one is te response?

Temperature is the explanatory variable and ice cream sales is the response because a city's temperature could explain the amount of ice cream sales.

A city planner says, "The typical commute to work for someone living in the city limits is less than the commute to work for someone living in the suburbs." What does this statement mean?

The center of the distribution of commute times for a city-dweller is less than the center of the distribution for those living in the suburbs.

Suppose 50 married couples are asked to provide their ages. For all couples, the husband is exactly 2 years older than his wide. For example, a 50-year old husband has a wife who is 48 years old. What is the best estimate of the correlation coefficient between the ages of husbands and their wives?

The correlation coefficient between the ages of husbands and wives is equal to 1

Below is the standard deviation for extreme 10k finish times for a randomly selected group of women and men. Chose the statement that best summarizes the meaning of the standard deviation. Women: s=0.16 Mean: s=0.25

The distribution of women's finish times is less varied than the distribution of men's finish times

Which of the following statements is characteristics of the sampling distribution of a sample proportion?

The mean of the sampling distribution is the same as the mean of the population from which the data were sampled

The distributioons of income in the United States is strongly skewed to the right. Which of the following is true?

The median income is smaller than the mean income

Ticket sales per hour = -631.25 +11.25 (current temperaure in F) Choose the statement that best states the meaning of the slope in this context.

The slope tells us that a one degree increase in temperature is associated with an average increase in ticket sales of 11.25 tickets

Suppose we have a distribution of the number of "friends" all users of a popular social media site have. What measure of spread would be best to describe this data?

The spread should be described with the IQR because the distribution will be skewed to the right.

Consider the following statement "My child was bullied on the school bus and so was my neighbor's child, so obviously, bullying is a big problem on school buses and something needs to be done about it!" What is wrong with this statement?

The statement is anecdotal

Negative trend line

The trend line goes downwards from left to right

Is the following an example of theoretical probability or empirical probability? A card player declares that there is a one in thirteen chance that the next card pulled from a well-shuffled, full deck will be a queen.

Theoretical

The following data table is organized which method? Gender- Age- Male. 35 Female. 42 Female. 33 Male. 37 Female. 39

This is stacked data because each row represents one person

Data can be defined as numbers in context. Suppose you are given the following set of numbers: 1.73,1.83, 1.57, 1.88, 1.70, 1.65. What additional information would allow you to define these numbers as data?

Units of measurement. This could represent the heights of six 20-year-olds, in meters.

In the NBA, the correlation between "steals per game" and "blocked shots per game" is found to be 0.8045. Choose the statement that is true about the coefficient of detemrination.

When given as a percent, the coefficient of determination is always between 0 and 100%, the coefficient of determination, r^2, is equal to approximately 0.6472, the coefficient of determination states that about 64.72% of the variation in blocked shots per game is explained by steals per game

Positive trend

When the dots in a scatter plot go up. Both sets of data increase together

What is a statistic?

a number describing a sample

What is a parameter?

a number describing a whole population

In a survey, married couples were asked, "Do you have children?" The response was electronically recorded as "1" for yes and a "0" for no. This is an example of ?

coded categorical data

What is a confidence interval?

uses data from a sample to estimate a population parameter

What is a hypothesis test?

uses data from a sample to test a specified hypothesis