Sampling & Experiments
Neither the subject nor those who measure the reponse variable know which treatment a subject received.
What is a double-blind experiment?
An interpretation of P-value = 0.03, alpha = .05
What is "we reject the null hypothesis, and have enough evidence to support the alternative hypothesis"?
The formula to algebraically identify outliers
What is Q1 - 1.5(IQR) and Q3 + 1.5(IQR)?
The probability of rolling a fair die and getting three 4s in a row. (Fraction or decimal)
What is P(rolling three 4s) = P(4)*P(4)*P(4) = P(4)^3 = 1/216 = .0046?
Given N(12,3); its the value of P(X < 8) (decimal)
What is normcdf(-9999, 8, 12, 3) = .091?
A Coke vs. Pepsi taste test is a common form of this experimental design
What is matched pairs?
An interpretation of the slope in the least-square regression line, y = 15 - 4x
What is "For every one unit increase in the explanatory variable, there is on average a 4 unit decrease in the reponse variable"?
The formula to calculate the expected value, E(x), of a discrete random variable
What is "the sum of the products of the values of x and their respective probabilities?"
The probability of pulling a red card or queen from a standard deck of 52 cards. (fraction or decimal)
What is P(red or queen) = P(red) + P(queen) - P(red and queen) = 26/52 + 4/32 - 2/32 = 28/52 = .54?
The probability of at least 8 successes in 12 trials given a probability of success of 45%.
What is binomcdf(12, .45, 8, 12) = .11?
When some groups in the population are left out of the process of choosing a sample
What is undercoverage?
An interpretation of a z-score of -3.45
What is "The data value is 3.45 standard deviations below the mean"?
How to determine if two events, A and B, are independent.
What is P(B|A) = P(B) or
P(A and B) = P(A)P(B)?
If a distribution of IQ scores is N(100,15), this is the probability of an IQ at least 110.
What is z=(110-100)/15 = 0.67; table = .7486; p = 1 - .7486 = .2514
It the value of the critical value, z*, for a 92% confidence interval
What is invNorm(.04) = -1.75 = 1.75?
The population is divided into groups. Some groups are randomly selected and all individuals in the chosen groups are sampled.
What is cluster sampling?
An interpretation of a 95% Confidence interval's result of (.1,.3) while the null hypothesis is p = .25
What is "We fail to reject H0. We do not have enough evidence for Ha"?
How to calculate a standard deviation sigma_(a+b), given that you know sigma_a and sigma_b.
What is the square root of the sum of the variances of the two random variables?
The probability of obtaining the first success on the 5th trial given that the probability of success is p = .4. (decimal)
What is P(X=5) = .4(1-.4)^4 = .052
It's the 95% confidence interval for a random sample of size 40, sample mean of 10 and sample standard deviation of 2.1. (give the CI)
What is tInterval(10, 2.1, 40, .95) = (9.33, 10.67)?
A variable that is not part of the study that can affect the response variable.
What is a lurking variable?
An interpretation of the condition: np = 15; n(1-p) = 9
What is "The normal probability condition is not met"
How to find the expected count for a value in a chi square 2-way test
What is the row total times the column total divided by the grand total?
The probability for finding more than 13 successes in 15 trials if the probability of success is p = .75 (do not use calculator function)
What is P(X>13)
= P(X=14)+P(X=15)
= .080?
This describes a graph where the mean is greater than the median.
What is skewed right?