Sampling & Experiments
Interpretations
Important Things You May Have Forgotten
Probability Rules!
Calculator Commands
100
Neither the subject nor those who measure the reponse variable know which treatment a subject received.
What is a double-blind experiment?
100

Decision made in Hypothesis Test if P-value = 0.001

What is "since the P-value is less than any reasonable significance level, we reject the null hypothesis, and conclude there is significance evidence to support the alternative hypothesis"?

100
How to identify outliers for univariate data
What is Q1 - 1.5(IQR) and Q3 + 1.5(IQR)?
100

T the probability of rolling a fair die three times and getting three fours.

What is P(rolling three 4s) = P(4)*P(4)*P(4) = P(4)^3 = 0.004

100
The correlation coefficient between L1 and L2
What is STAT-->CALC-->8:LinReg(a+bx) L1, L2?
200

Primary Reason for Blocking in Experiments

Reduce Variation in Responses

200

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"?

200
The expected value of a discrete random variable
What is the mean of the random variable found by summing the products of the values of x and their repsective probabilities?
200
The rule for the probability of pulling a red or queen from a standard deck of cards.
What is P(red or queen) = P(red) + P(queen) - P(red and queen)?
200
The probability of at least 8 successes in 12 trials given a probability of success of 45%.
What is DISTR (or 2nd VARS)--> 1-binomcdf(12,.45,7)?
300
When some groups in the population are left out of the process of choosing a sample
What is undercoverage?
300
A test statistic for a one sample z-test for difference in proportions gives a z-stat = 1.45.  Find its p-value if the test if two-sided.  

What is 0.147

300
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)?
300

The probability of rolling a sum of 7 on two dice, given one of the dice is even.  

What is  1/6

300

The z* for a 92% confidence interval

What is DISTR (or 2nd VARS)--> invNorm(.04) = 1.75

400

The population is divided into groups by some "like" characteristic and then a random sample is selected from each of these groups.  

What is stratified random sampling

400
Sample size needed to estimate the population proportion to within 0.045 of the actual using 95% Level confidence

n = 475

400
The standard deviation of the difference between two random variables.
What is the square root of the sum of the variances of the two random variables?
400
The rule for finding the probability of obtaining the first success on the 5th trial.
What is P(X=5) = p(1-p)^4
400

X~B(14, 0.3)Calculator Command for P(X < 8)  

binomcdf(14, 0.3, 7) 

500
The effects of two variables on the response cannot be distinguished from each other.
What is confounding?
500

The 95% confidence interval (-4.25, -1.33) for the difference of two means (mean #1 - mean #2).  Does this provide evidence of a significant difference in these means?  WHY?

Yes, the interval does NOT contain 0, therefore we have evidence of a significant difference.  

500

Formula for finding the slope of the linear regression line if you know the correlation and the summary statistics for each variable.  

Slope = (r)(sy/sx)

500

The chance of guessing exactly 4 question correct out of 10 True/False Questions by Guessing.  

What is .205
500

Find the area between z=1.45 and z = 2.45 on a normal distribution curve.  

What is normalcdf(1.45, 2.45, 0, 1) 

M
e
n
u