Equations
Z score
(x-µ)/o-
Mean
The average divided by the number of numbers
What was Unit 9 about?
Inference for Quantitative Data
When do we use the geometric distribution?
Two possible outcomes, fixed probability, independent trials
What is the variability in a sampling distribution?
µp hat
µp hat = p
Confidence interval
The probability that "a population parameter will fall between a set of values for a certain proportion of times"
What was unit 5 about?
Sampling distributions
What is the Standard Deviation for geometric distributions?
σ=(√(1-p))/p
Find the p-value and interpret the correct conclusion for a t-test for the slope of the true regression line between a cat's body length and their weight, when H0=0 and Ha:ß ≠ 0.
p-value = .585; We do not have convincing evidence of a linear relationship between a cat's body length and a cat's body weight.
Smean
S/√(n)
Standard deviation
The measure of the amount of variation around the mean
Free 300 points
300 points
When do we use the binomial distribution?
Two possible outcomes, fixed probability, and independent trials.
In 2021, people are leaving the workforce in droves. This is being called "The Great Resignation" and one of the theories of why this is happening has to do with pay; people are not willing to work for low paying jobs any longer. Suppose that at a certain computer software company, if offered a higher salary at a competing software company, 75% of employees would switch over to the other company. If you take an SRS of 50 employees, what is the probability that between 73% and 77% would be willing to switch companies if offered a higher salary?
.2561
Standard deviation of a binomial distribution
σX=√(np(1-p)
Chi square statistic
A hypothesis test used when the sample sizes are large.
A job that uses statistics
A statistician
How many trials do you do for a binomial distribution?
You have a fixed amount.
What is the distribution of values taken by a statistic in all possible samples of the same size from the same population called?
The sampling distribution of the statistic.
Standard Error of Sample Statistic for Two Populations
Sx1-x2 = √((S1^2)/n1)+(S2^2)/n2))
SRS
Simple Random Sample
The number of units we've finished in Statistics
9
How many trials do you have for a geometric distribution
You have as many trials as it takes until you get to the first success.
If a statistic used to estimate a parameter is such that the mean of its sampling distribution is equal to the true value of the parameter being estimated, what is the statistic said to be?
Unbiased.