STATS HELP

NEED HELP WITH 100% CORRECT ANSWER

What is Statistics?

A) The science of collecting, describing, and interpreting data.

B) The science of data and variables.

C) The art of interpretation.

D) The art of summarization and graphical representation.

2.

Consider the sample 2,4,7,8,

9.

Find the mean, x̄

A) 4

B) 5

C) 6

D) 7

3.

The following data are cost (in cents) per ounce of nine different brands of goat cheese:27, 56, 37, 45, 69, 39, 52, 47, 32. Compute the variance and the standard deviation for this data set.

A) 152.33, 10.95

B) 167.86, 12.95

C) 148.52, 15.95

D) 135.67, 11.95

4.

There are two types of numerical data: discrete and continuous. Which is an example of discrete.

A) 21, 4, 15, 16

B) 4-21

C) Both of the above

D) None of the above

5.

A variable is any characteristic whose value may change from one individual or object to another. Which is an example of a variable?

A) Calculator brand

B) Number of textbooks purchased

C) Distance to the university

D) All of the above

6.

There are two methods commonly used in data collection.

They are:

A) Surveys and questionnaires

B) Social media and the internet

C) Experiments and Observational studies.

D) None of the above

7.

What type of graph is a bar graph with the bars arranged from the most numerous category to the least numerous category?

A) pie chart

B) pareto diagram

C) spider chart

D) All of the above

8.

The definition of a population is:

A) a subset of the total of individuals or objects which information is desired.

B) a subset of a sample of individuals or objects which information is desired.

C) an entire collection of individuals or objects which information is desired.

D) a partial collection of individuals or objects which information is desired.

9.

In some studies, attention focuses on a single variable. Other studies will focus on two variables. When a study focuses on two characteristics, such as age and weight, the data set will consist of pairs of numbers, such as (68, 192). The age is 68 and the weight is 192. When a study focuses on two characteristics it is called a:

A) bivariate data set

B) univariate data set

C) trivariate data set

D) quadvariate data set

10.

The primary purpose of linear correlation is to measure the strength of a linear relationship between two variables. Scatter diagrams measure that relationship. A scatter diagram can reflect:

A) no correlation

B) positive correlation

C) negative correlation

D) All of the above

11.

The coefficient of linear correlation, r, is the numerical measure of the strength of the linear relationship between two variables. The linear correlation coefficient, r, always has a value between:

A) -1 and +1

B) 0 and +1

C) -10 and +10

D) None of the above

12.

A probability of an event is:

A) the relative frequency with which that event can be expected to occur.

B) the number of times a variable has occurred.

C) the number of trials in an event.

D) None of the above.

13.

A random variable assumes a unique numerical value for each of the outcomes in a sample space of a probability experiment. This is called the random variable value. Numerical random variables can be subdivided into two classifications.

They are:

A) samples and populations

B) parameters and percentages

C) discrete random variables and continuous random variables

D) none of the above

14.

Lengths of newborn babies (in centimeters) are known to be normally distributed with a mean of 50 centimeters and a standard deviation of 5 centimeters. How would you denote the number 5?

A) X-Bar

B) s

C) μ

D) σ

15.

The regression output and scatterplot are for average commercial insurance payments, in thousands of dollars, made to ten hospitals in a certain city for heart valve surgery vs. coronary bypass surgery. Which is these is your best guess for the correlation?

A) -80

B) -9

C) +.9

D) None of the above

16.

The empirical rule states that for a normal distribution almost all data will fall within 3 standard deviations from the mean. What percentage of the data will fall within the first standard deviation?

A) 34%

B) 68%

C) 95%

D) 99.7%

17.

The New York Times reported on the prices of 40 different brands of lipstick.

Here is a histogram of the data.

Which one of these is the mean price?

A) $17

B) $18

C) $19

D) $20

18.

The relationship between average reading and average writing SAT score was examined for a sample of 19 schools. The relationship is apparently:

A) weak and negative

B) strong and negative

C) weak and positive

D) strong and positive

19.

Even when accounting for disparities in the 65-and-older population’s diseases, ages or other health-related factors, there’s still a significant difference in mortality based on walking.” This shows the researchers controlled for

A) the placebo effect

B) the Hawthorne effect

C) confounding variables

D) lack of realism

20.

Students lie, cheat, steal, but think they are good “The Josephson Institute, a Los Angeles-based ethics institute, surveyed 29,760 students at 100 randomly selected high schools nationwide, both public and private. All students in the selected schools were given the survey in class; their anonymity was assured…The survey found that 35 percent of boys and 26 percent of girls—30 percent overall—acknowledged stealing from a store within the past year…Cheating in school is rampant and getting worse. Sixty-four percent of students cheated on a test in the past year and 38 percent did so two or more times, up from 60 percent and 35 percent in a 2006 survey.” What percentage of students reported cheating just once in the past year 2007?

A) 6%

B) 16%

C) 26%

D) 36%

21.

In Excel, the function to calculate the measure of centrality for the mean is:

A) Average

B) mean

C) median

D) mode

22.

A masters thesis by M. Purser at the University of Washington in 1988 looked at soil densities in a conifer forest, before and after clearcut logging in the area. These histograms show 32 pre-logging densities and 38 post-logging densities, recorded in grams per cubic centimeter. Unlike most before-and-after designs, this was a two-sample study: the same sample of soil could not be assessed twice. First compare the histogram’s centers: when were the densities higher on average?

A) before logging

B) after logging

C) neither

23.

True or False: The first quartile and the 25th percentile are the same.

A) True

B) False

C) Neither true of false there isn’t enough information.

24.

Correlation does imply causation.

A) True
B) False

25.

The line of best fit is also called the trend line. It is a straight line that best represents data on a scatter plot. A line of best fit must pass through all of the points represented on the scatter plot.

A) True
B) False