Formulas
What is the formula for sample mean in a sampling distribution?
What is needed to determine causation in experiments.
Random Assignment
What is the acronym for describing a scatterplot
DUFS (Direction, Unusual Features, Form, Strength)
All probabilities add to what whole number
One
What is needed to generalize results to the population.
random selection
what is the basic formula for z-score
z = test statistic - parameter/standard deviation
What do you use in the selection step when writing a sampling method in order to randomize the integers
Random number generator
What are the 5 different things that you need to explain when describing a distribution
Context, Shape, Unusual Features, Center, Variability
two events cannot happen together they are
mutually exclusive
If the t-test statistic chart for a linear regression test shows a p-value of 0.12, what is the p-value of a one-sided linear regression t-test?
p-value = 0.06
What is the basic formula for a confidence interval
parameter +- critical value(standard error)
A scientist studying soil acidity collected soil samples from a plot of land with a stream running through it. The soil samples came from land located on only one side of the stream. What is the potential source of bias that might result from the sampling method?
Undercoverage bias
How would you interpret the mean of 2.5 for a binomial distribution on the number of questions guessed right on a quiz
If many, many quizzes are done, the average number of correct answers is 2.5 correct.
In a binomial distribution the conditions that you must check are
B-successes and failures
I-independence
N-number of trials is fixed
S-same probability
How do you find the degrees of freedom for a linear regression test
df = n - 2
This formula is used when calculating a the z-score of a two sample test for proportions.
z = ^p1 - ^p2/ square root of ^pc(1-^pc)(1/n1 + 1/n2)
What is the disadvantage(s) of using a systematic random sample
You need an ordered list of the population
Interpret a residual of -3.2 for Rohan's height in feet.
Rohan's actual height is 3.2 feet less then the height predicted with the LSRL
If the probability of something happening is 0.4 what is the probability it happens 3 times in a row and then does not happen?
0.0384
What are the conditions for a linear regression test
L- Linear relationship in scatter plot with no leftover residual pattern
I- Independence: 10% Condition
N- Dot plot of residuals shows no skew or outliers
E- Equal SD: residual plot shows similar variability for all x values or shows no left over sideways Christmas tree pattern
R: Random selection
What is the formula for finding b in an LSRL
b = r(Sy/Sx)
A principal at a large high school is proposing a new lunch menu that serves healthier alternatives for lunch that value taste less. She wants to know what proportion of the student body is in favor of this. Explain how the principal could take a stratified random sample, using grade level as a strata, sampling a quarter of each grade, given that each grade level has 100 students
How do you interpret the standard deviation/error of the slope of an LSRL
If we repeat the sampling/assignment many, many times, the slope of the sample LSRL typically varies by SEb from the true slope.
A fair coin will be tossed 3 times. The set of outcomes can be described by the ordered triplets. {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT} where H represents heads and T represents tails. What is the probability that all three tosses result in heads, given that the three tosses result in more heads than tails?
1/4
What does the margin of error account for and what does it not account for
MOE accounts for variability, but does not account for nonresponse, response, and undercoverage bias