Exam (elaborations)
Statistics 231: Exam 4 questions with answers
- Course
- Stats 231
- Institution
- Stanford University
Statistics 231: Exam 4 questions with answers
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Statistics 231: Exam 4 questions with answersDefine Hypothesis Test: - ** VERIFIED ANSWERS🔰 ✔✔A hypothesis test is a process that
uses sample statistics to test a claim about the value of a population parameter.
*For a hypothesis test, to decide whether it is true or false, you do something unusual - you
assume the given information is correct.
We test a claim by analyzing sample data to choose between two explanations, what are
these two explanations? - ** VERIFIED ANSWERS🔰 ✔✔1.) The sample results could
easily occur by chance.
2.) The sample results are not likely to occur by chance.
Transform a simple statistic to a z-score: - ** VERIFIED ANSWERS🔰 ✔✔To transform a
simple statistic to a z-score, use the formula: z = (x - μ)/(σ/√n)
Z-score formula: - ** VERIFIED ANSWERS🔰 ✔✔The basic z-score formula for a sample is:
z = (x - μ)/σ
- For the problem, you are given:
1.) Population mean: μ
2.) Population standard deviation: σ
3.) The specific x-value you wish to convert to a z-score.
,Define z-score: - ** VERIFIED ANSWERS🔰 ✔✔A z-score is the number of standard
deviations from the mean a data point is. But more technically, it's a measure of how many
standard deviations below or above the population mean a raw score is.
*A z-score is also known as a standard score and it can be placed on a normal distribution
curve.
For a hypothesis test, when you are not given the level of significance (α), what value do you
use? - ** VERIFIED ANSWERS🔰 ✔✔When you are not given the level of significance (α)
in a problem, you use the most common:
α = 0.05
List the steps of the Hypothesis Test: - ** VERIFIED ANSWERS🔰 ✔✔- State the research
question.
- State the statistical hypothesis.
- Set decision rule.
- Calculate the test statistic.
- Decide if result is significant.
- Interpret result as it relates your research question.
Define Statistic hypothesis: - ** VERIFIED ANSWERS🔰 ✔✔A statistical hypothesis is a
claim or statement about a property of a population.
, *A statistical hypothesis is a statement about a population parameter.
How to test a Population parameter: - ** VERIFIED ANSWERS🔰 ✔✔- State a pair of
hypotheses: Null hypothesis and Alternative hypothesis
1.) One hypothesis that represents the claim.
2.) The other that represents the complement of the claim.
- When one of these hypotheses is false, the other must be true.
- Either hypothesis - the null hypothesis or the alternative hypothesis - may represent the
original claim.
List the properties of a Null hypothesis: - ** VERIFIED ANSWERS🔰 ✔✔- Denoted by H0;
which is read as "H sub-zero" or "H naught."
- A statistical hypothesis that contains a statement of equality.
- Uses the equality symbols: ≤, ≥, or =.
- We assume the null hypothesis is true and reach a conclusion to either reject the null
hypothesis or fail to reject the null hypothesis.
List the properties of a Alternative hypothesis: - ** VERIFIED ANSWERS🔰 ✔✔- Denoted
by H1 or HA; which is read as "H sub-α."
- The complement of the null hypothesis.
- If the statement in the null hypothesis is not true, then the alternative hypothesis must be
true. A statement that must be true if the null hypothesis is false.
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