Estimation, Hypothesis Testing for One Sample Flashcards
Inferential Statistics?
drawing conclusions about a population based on the information in a sample
Parameter?
-measured characteristic of a population
Statistic?
-measured characteristic of a sample
Point Estimate? estimate of population mean?
-single value used to approximate a population parameter -uses a sample data to calculate a single value -estimate of population mean= sample mean
Interval Estimate?
-2 numerical values defining a range that with a specified degree of confidence, includes the parameter being estimated
T- distribution factor?
-use if we are not given the standard deviation
Hypothesis?
-statement or claim about a population
Hypothesis Testing?
- determine whether or not the available data are compatible with the statement
- aids in making a conclusion about a population y examine a sample from the population
Null Hypothesis?
Alternative Hypothesis?
Ho= states that a population parameter is equal to a certain value
HA= hypothesis that contradicts Ho (OFTEN WHAT YOU HOPE TO SHOW)
-both cover all possible values of the parameters under study
Is Ho not proven if is is not rejected?
no, either due to insufficient data to show Ho is false
3 steps in the Fisher Method of determining Ho and HA?
- state the claim
- state the counter claim
- assign the claim with he equality to Ho and the remaining claim to HA
Ho true?
Ho false?
Ho true= do not reject Ho
Ho false= reject Ho
Type 1 error?
Type 2 error?
Ho is true, but it is rejected
Ho is false but it is not rejected
Z-critical point and type 1 error?
z-critical value is the trigger point, point at which you reject the null hypothesis (type 1 error)
5-Steps to Hypothesis Testing?
- define null and alternative hypothesis
- specify test statistic
- set up decision rule
- calculate test statistic
- make statistical decision
P-Value?
-probability of obtaining a test statistic equal to or higher than the one observed if Ho is true
Large P values=?
Small P values=?
Large p-values= Ho is quite plausible given the data
Small p-values= Ho is implausible
P-value vs critical value?
- Reject Ho if p-value is less than a (the value that you are catering Ho is correct ie. a=0.05= 95% sure) (for fishers approach)
- Reject Ho if test statistic is greater than the critical value
- p-value and critical value are equivalent in terms of the decision to reject Ho
- P-value is often preferred as it indicated strength go the evidence
