Hypothesis Formation
What is it called when you reject the null hypothesis when there is not enough evidence to?
Type 1 Error
What is the difference between a binomial and geometric distributions?
A binomial distribution counts the number of successes under a fixed number of trials while a geometric distribution counts the number of trials to get a success.
What does parameter mean?
A numerical summary of a population.
What does a 95% confidence interval mean?
About 95% of intervals from repeated samples would capture the true population parameter.
What kind of graph is best for displaying the distribution of one quantitative variable?
Histogram
What does a P value of 0.03% mean if alpha is 0.05%?
There is a statistical significance within the equation.
A coin is flipped 3 times. What is the probability of getting exactly 2 heads?
⅜ = 0.375
8 total outcomes and 3 favorable outcomes: HTH HHT THH
What is a statistic?
A numerical summary of a sample.
If a 95% confidence interval for a mean is (12, 18), what is the margin of error?
3
(18-12)/2
What does a right skewed distribution look like?
The tail extends to the right
What are the 3 checks needed for an A<B hypothesis?
Random variable, normal/10%, and large count
If given a MCQ with 4 choices, what is the probability of guessing correctly on the third attempt?
9/64
Fail twice and then succeed: (¾)(¾)(¼)
What is undercoverage bias?
When a group of people is underrepresented in a sample.
If a confidence interval for μ is (20, 28), what is the point estimate?
24
If the dots are close together on a dot plot towards the positive expected value, what does that say about the R value?
The R value is close to +1
If there is not enough data in the sample for a large count, what 2 requirements are needed to make the hypothesis work?
No skewed values or outliers in the graph
Assuming A and B are independent, if P(A) is 0.6 and P(B) is 0.5, what is P(A and B)?
0.30
(0.6)(0.5)
What is the difference between observational studies and experiments?
Observational studies observe subjects while experiments include treatments.
A 95% confidence interval for p is (0.42, 0.58). Does this provide evidence that p=0.50?
Yes, 0.50 falls within the given interval.
What does it mean when a scatter plot has a strong positive association?
As one variable increases, the other also increases.
A researcher conducts a hypothesis test with a = 0.05 and gets a p-value of 0.08. What is the appropriate conclusion?
They should fail to reject the null hypothesis because the p-value is greater than alpha. There is not sufficient evidence to support Ha.
A binomial setting has n = 12 and p = 0.4. What is the expected value?
4.8
E(x) = np = 12(0.4)
What is the difference between AUB and A&B
AUB is the probability of getting either while A&B is the probability of getting both at the same time
If the confidence interval for P is (72, 87), Is 68 match within the interval range. If not, explain why it does not fit the interval range?
90 goes beyond the interval range, meaning that 90 is not a confident value
If a residual plot shows a curved pattern. What does this suggest?
A linear model is not appropriate to use because the relationship is non-linear.