Chapters 1-3 Psychstats Pretest

The mean is the most representative and is used most often. Only in skewed data would the median be referred to as the more accurate representation.

When the data is skewed by a large outlier or extreme score (1), then the mean is biased and is no longer a good represenation for all of the scores. The median is now the better representation.

"All College Students" is the large population from which the sample ("Maryville Students") are drawn.

Following the equation Z=(X-M)/SD, Z= (54 - 70)/5 = -4

According to the equation Probability= Successful outcomes/All Possible outcomes, p= (61 + 24) / 115

Inferential statistics involves drawing conclusions or making inferences about a population based on a sample. It allows researchers to generalize their findings and make predictions about the larger population. This is in contrast to descriptive statistics, which simply summarize and describe the data without making any inferences. Variability refers to the spread or dispersion of data, the Z distribution is a specific type of probability distribution used in hypothesis testing, and probability is the likelihood of an event occurring.

This selection would be considered haphazard because the subjects are chosen without any specific criteria or randomization. It is a careless and unplanned selection process, which may introduce bias and affect the validity and generalizability of the study's findings.

The symbol σ2 represents the variance of the population. Variance is a statistical measure that quantifies the spread or dispersion of a set of data points. It is calculated by taking the average of the squared differences between each data point and the mean of the population. The symbol σ represents the standard deviation of the population, which is the square root of the variance. Therefore, σ2 is the correct symbol for the variance of the population.

Variance is the Standard Devation squared. By using Standard deviation, we are able to measure how spread out the scores are in "non-squared" units. For instance, saying "the scores are spread out on average about 2 units away from their mean" makes more sense than "the scores are spread out on average about 4 units squared away from their mean"

A variable is the characteristic being measured in a study or experiment, while a value is a possible number or category that a score can have within that variable. In other words, the variable represents the concept or attribute being studied, while the value represents the specific measurement or category within that concept. For example, in a study on height, "height" is the variable being measured, and values could be "5 feet 10 inches" or "6 feet 2 inches".

Since the tail is being pulled in the positive (right) direction, this is a right skewed [aka positive skewed] distribution

According to the equation Variance=SS/N, SS=82.5, Variance= 8.25, SD=2.88

1.64 is the corresponding Z score to be ing the top 5%. SD= Square root of 25 = 5. Following the equation Z=(X-M)/SD, 1.64= (X - 70)/5 = 78.2

Expected Relative Frequency refers to the number of times an event is expected to occur in the long run, based on probability. It takes into account the likelihood of the event happening and provides an estimate of the frequency of occurrence over a large number of trials. This concept is commonly used in statistics and probability theory to make predictions and analyze data.

Equal interval ratio variables are numeric variables that can have an absolute zero (you can be apart of 0 clubs)

John's score of 12 falls 2 standard deviations above its mean, while Kayla's score of 86 only falls 1.3 standard deviations about its mean. John has the more extreme score because he falls further away from the mean, which means he actually received the higher score.