Statistics Samenvattingen, Aantekeningen en Examens

Statistics Test A

Statistics Test

Statistics

Stats, Unit 1

What are Statistics

How do you check if there is outliers?calculate IQR; anything above Q3+1.5(IQR) or below Q1-1.5(IQR) is an outlier If a graph is skewed, should we calculate the median or the mean? Why?median; it is resistant to skews and outliers If a graph is roughly symmetrical, should we calculate the median or the mean? Why?mean; generally is more accurate if the data has no outliers What is in the five number summary?Minimum, Q1, Median, Q3, Maximum Relationship between variance and standard devia...

The manufacturer of a soccer ball claims that only 3% of the soccer balls produced are faulty. An employee of this company examines the long-run relative frequency of faulty soccer balls produced as shown in the graph.Which conclusion can be drawn from this graph?The company's claim seems to be true because the graph shows that when 50 soccer balls were tested, only about 3% of them were faulty.We should not believe the company's claim that only 3% of their soccer balls are faulty be...

Explain the difference between a population and a sample.A population is the entire group that is being studied while a sample is a subset of the population that is being studied. A(n) _________ is a person or object that is a member of the population being studied.Individual ________ statistics consists of organizing and summarizing information collected, while ________ statistics uses methods that generalize results obtained from a sample to the population and measure the reliability...

Alicia would like to know if there is a difference in the average price between two brands of shoes. She selected and analyzed a random sample of 40 different types of Brand A shoes and 33 different types of Brand B shoes. Alicia observes that the boxplot of the sample of Brand A shoe prices shows two outliers. Alicia wants to construct a confidence interval to estimate the difference in population means. Is the sampling distribution of the difference in sample means approximately norm...

Positive correlation As one variable increases, the other variable increases Negative correlation As one variable increases, the other decreases A point on the scatter plot represents how many values? 2 (X and Y) Relationship between linear and scatter plot diagrams? The regression line is the bestfitting line through a scatter plot If you see the notation (E X)(E Y) what should you do? First sum the Xs, then sum the Ys, then multiply the sums If you see the notation E XY what should you...