Name that Inference Procedure
A school claims that 15% of its students are out of uniform each day. The principal believes that this number is over-exaggerated and that almost all of the students wear them. The principal wants to test it at α =0.05. The principal takes a random sample of 80 students and finds that 12 are out of uniform.
What is a 1-proportion z-test?
df = sample size - 1
What is the degrees of freedom for one-sample t procedures?
A value that is used to estimate a population parameter
What is a point estimate?
To calculate a one-sample t-test for means you use the ___ calculator command.
What is stat->tests-> T-Test?
Name the conditions that need to be checked for a one-sample z-test and z-interval.
What is.. 1. random 2. 10% = n<0.10N 3. large counts= np ≥ 10 and n(1-p) ≥ 10
Your parents claim that you only study for 55 minutes a night. You want to prove to them that you study for longer. They decide to record your study time for 30 nights. From this they find you average 35 minutes a night and have a standard deviation of 10.
What is a 1-sample t-test for a mean?
\hat{p}\pm z^*\sqrt{\frac{\hat{p}(1-\hat{p})}{n}}
What is a one-sample confidence interval for a population proportion?
Probability of obtaining a test statistic as extreme or more extreme than the observed test statistic when null hypothesis is assumed to be true
What is a p-value?
To calculate a one-samle t-interval for means you use the ____ calculator command.
What is stat-> tests-> T-Interval?
\chi^2=\Sigma\frac{("observed"-"expected")^2}{"expected"}
What is a chi-square test statistic?
140 out of 170 men report that they eat out at least 3 times a week and 170 out of 340 women report they eat out at least 3 times a week. A researcher wants to estimate the true percentage difference between the men and women.
What is a 2-sample confidence interval for proportions?
df= # of categories - 1
What is degrees of freedom for x2 GOF test?
1. a number that describes the population 2. a number that describes the sample
1. What is a parameter? 2. What is a statistic?
To calculate a one-sample z-test for proportions use the ____ calculator command.
What is stat-> tests-> 1-PropZTest?
The probability that a test will correctly reject the null hypothesis, given that the alternative hypothesis is true.
What is the power of a test?
You want to know if there is an association between the age of the person and the type of phone they have. This is on the basis of people being of older age are more likely to only have a landline, while those who are younger are more likely to have a cellphone. Use a level of 5% significance.
What is a Chi-Square test for Independence?
t=\frac{b-0}{\frac{s}{s_x\sqrt{n-1}}} calculates the test statistic for this significance test.
What is the test statistic for a linear regression t-test for slope?
This states when a sample size is sufficiently large, then the sampling distribution of sample means will be approximately normal. n ≥ 30.
What is the central limit theorem (CLT)?
To perform a \chi^2 Goodness of Fit test use the ____ calculator command.
What is stat-> tests-> \chi^2 GOF-Test ?
Occurs when the alternative hypothesis is true and we fail to reject the null hypothesis (false negative).
What is a type II error?
Researchers want to know if Banana Boat is a more effective sunscreen brand than Sun Bum. They randomly chose 30 people to come and test each brand. The researchers randomly select which arm will have Banana Boat and which arm will have Sun Bum. They compare the results at a 5% significance level.
What is a Matched Pairs T-Test for a mean difference?
z=\frac{(\hat{p}_1-\hat{p}_2)-0}{\sqrt{\frac{\hat{p}_c(1-\hat{p}_c)}{n_1}+\frac{\hat{p}_c(1-\hat{p}_c)}{n_2}}}
where \hat{p}_c=\frac{X_1+X_2}{n_1+n_2}
This calulates the test statistic for this significance test.
What is the test statistic for a two-sample z test for the difference of population proportions?
When estimating a population parameter, the statistic is unbiased if, the center of the sampling distribution is equal to the population parameter being estimated.
What is an unbiased estimator?
To calculate a x2 test for homogeneity or independence use the ____ calculator command.
What is stat-> tests-> \chi^2 - Test ?
Define the two factors that can affect the width of a confidence interval.
What is increasing the sample size decreases the width and increasing the confidence level increases the width?
Is there a relationship between a person's body temperature and their resting pulse rate? A researcher collected data on x= body temperature (in oF) and y= pulse rate (in beats per minute) for each of 20 randomly selected students at a university. The equation of the LSRL relating these two variables is \hat{y}=-408.904+4.944x and the standard error of the slope is 2.8712 . Do these data provide convincing evidence at the 1% significance level of a linear relationship between body temperature and resting pulse rate for students at this university?
What is a linear regression t-test for slope?
\bar{x}\pm t^*\frac{s}{\sqrt{n}}
What is a one-sample t interval for a population mean?
What is the 10% condition?
t^*="tcdf"("area:"0.975, "df:"44) calculates the critical value for this.
What is the critical value for a t-interval with a 95% confidence level and a sample size of 45.
Name the conditions that need to be checked for a linear regression t-test and t-interval.
LINER - 1. Linear - is the scatterplot linear?
2. 10% Condition
3. Normal - check the graph of the residuals for strong skew or check the normal probability plot
4. Equal SD - check for similar scatter above and below the 0 line on the residual plot
5. Random Condition