Confidence Intervals
... sampling distribution. What this statement means is ***** If we could take all possible samples of size n, calculate the confidence interval in the formula above for each and every sample, then the proportion of confidence intervals containing the true value of the population proportion will be exac ...
... sampling distribution. What this statement means is ***** If we could take all possible samples of size n, calculate the confidence interval in the formula above for each and every sample, then the proportion of confidence intervals containing the true value of the population proportion will be exac ...
Hypothesis Testing
... our t-table does not give us all the information we have in the normal table, so we cannot get the p-value exactly. We can only choose from the α values available on the table or interpolate between them. (The Excel function TDIST gives the area under a t distribution to the right of a specified valu ...
... our t-table does not give us all the information we have in the normal table, so we cannot get the p-value exactly. We can only choose from the α values available on the table or interpolate between them. (The Excel function TDIST gives the area under a t distribution to the right of a specified valu ...
Hypothesis Testing to Compare the Difference in 2 Population Means
... Testing a Claim about the Difference in 2 Population Means (Independent Samples) Example 1 (Right Tail Test) A study was conducted to see if a two week instructional course helped fifteen year olds score better on their first written driving exam. A independent random sample was taken of 46 student ...
... Testing a Claim about the Difference in 2 Population Means (Independent Samples) Example 1 (Right Tail Test) A study was conducted to see if a two week instructional course helped fifteen year olds score better on their first written driving exam. A independent random sample was taken of 46 student ...
STA 291-021 Summer 2007
... This interval will contain μ with a 100(1-α)% confidence ◦ If we are estimating µ, then why it is unreasonable for us to know σ? Thus we replace σ by s (sample standard deviation) This formula is used for large sample size (n≥30) If we have a sample size less than 30 a different distribution i ...
... This interval will contain μ with a 100(1-α)% confidence ◦ If we are estimating µ, then why it is unreasonable for us to know σ? Thus we replace σ by s (sample standard deviation) This formula is used for large sample size (n≥30) If we have a sample size less than 30 a different distribution i ...
Module 10: Comparing Two Proportions
... Perform large-sample inferences (hypothesis test and confidence intervals) to compare two population proportions. Describe the relationship between the sample sizes, confidence level, and margin of error for a confidence interval for the difference between two population proportions. Determine the s ...
... Perform large-sample inferences (hypothesis test and confidence intervals) to compare two population proportions. Describe the relationship between the sample sizes, confidence level, and margin of error for a confidence interval for the difference between two population proportions. Determine the s ...
Sample and Population Variance
... deviation: both indicate the spread of the data distribution about the mean. In fact, the standard deviation is simply the square root of the variance. There are a number of reasons why the variance is calculated the way it is. As the formula for sample variance shows, the sum of the squared deviati ...
... deviation: both indicate the spread of the data distribution about the mean. In fact, the standard deviation is simply the square root of the variance. There are a number of reasons why the variance is calculated the way it is. As the formula for sample variance shows, the sum of the squared deviati ...
File - Glorybeth Becker
... If we have categorical data, then we must use sample proportions to construct a sampling model. Example: Suppose we want to know how many seniors in Maryland plan to attend college. We want to know how many seniors would answer, “YES” to the question, “Do you plan to attend college?” These response ...
... If we have categorical data, then we must use sample proportions to construct a sampling model. Example: Suppose we want to know how many seniors in Maryland plan to attend college. We want to know how many seniors would answer, “YES” to the question, “Do you plan to attend college?” These response ...
HOMEWORK #5, due Lecture \#7
... 2.1268. Also, we can think that since this interval doesn’t include 0 (no mean change), we can say that there is mean change in blood pressure over two years (with 95% confidence, of course) h. Is the p--value p < 0.05? - Yes, because 0 (:no mean change) is not included in the 95% confidence interva ...
... 2.1268. Also, we can think that since this interval doesn’t include 0 (no mean change), we can say that there is mean change in blood pressure over two years (with 95% confidence, of course) h. Is the p--value p < 0.05? - Yes, because 0 (:no mean change) is not included in the 95% confidence interva ...
Review for test I
... proportion of the observations will be less than 57 inch? c) If the heights have a mound shaped and symmetric histogram, what proportion of the students will be less than 60 and more than 69 inch? d) If nothing is known about the shape of the distribution, give an interval that will contain the heig ...
... proportion of the observations will be less than 57 inch? c) If the heights have a mound shaped and symmetric histogram, what proportion of the students will be less than 60 and more than 69 inch? d) If nothing is known about the shape of the distribution, give an interval that will contain the heig ...
Notes 9 - Wharton Statistics Department
... • Lurking variable: A variable that is associated with both average test score and student-teacher ratio. • In order to figure out whether a drop in studentteacher ratio causes higher test scores, we want to compare mean test scores among schools with different student-teacher ratios but the same va ...
... • Lurking variable: A variable that is associated with both average test score and student-teacher ratio. • In order to figure out whether a drop in studentteacher ratio causes higher test scores, we want to compare mean test scores among schools with different student-teacher ratios but the same va ...
Nonparametric Statistics
... less than or equal to the criterion, but also the mean rank for the sample predicted (in H1) to come from the population with the smaller median must be less than the mean rank in the other sample (otherwise the exact p = one minus the p that would have been obtained were the direction correctly pre ...
... less than or equal to the criterion, but also the mean rank for the sample predicted (in H1) to come from the population with the smaller median must be less than the mean rank in the other sample (otherwise the exact p = one minus the p that would have been obtained were the direction correctly pre ...
document
... The two-sample t procedures are more robust than the one-sample t methods, particularly when the distributions are not symmetric. Using the t Procedures • Except in the case of small samples, the condition that the data are SRSs from the populations of interest is more important than the condition t ...
... The two-sample t procedures are more robust than the one-sample t methods, particularly when the distributions are not symmetric. Using the t Procedures • Except in the case of small samples, the condition that the data are SRSs from the populations of interest is more important than the condition t ...
