What Test is it?
Walpole High School wants to know if statistics is too difficult. If less than 0.8 of students pass statistics, the statistics teachers will be fired and the class will not be taught ever again. 30 random stats students are selected and 26/30 of them passed. What test would they use?
One sample z-test for p
A GPA of 4.2 is 2 standard deviations above the mean of 3.8.
What value is being interpreted?
z-score
The town of Walpole wants to know if too many students are failing. They ask each student that enters the Walpole library if they are failing, then run a one sample z-test for p.
What did they do wrong?
Convenience sample, leading to response bias.
This measure for center is generally unaffected by skew.
Median
CLT should be met for you to proceed with a t-test
True
Tanay wants to estimate the amount of protein in the school's pizza. To do this, he takes a sample of 20 pizza slices from each lunch and analyzes them for their protein amounts. What test is being carried out?
One sample t-interval for μ
0.87 of the relationship between gas mileage and year of production since 1990 can be explained by the linear regression line y = 2.34x + 20.
What value is being interpreted?
r2
Massachusetts department of education wants to send an email to each student with a survey on classroom condition. Each student is then told about the optional survey at the end of the school day.
What bias is presented in this study?
Non-response bias
The operation NEVER to be used when combining standard deviations for a two sample procedure.
Subtraction
Zip code is a categorical variable
True
Joe wants to figure out if the track team is better than the soccer team to be able to recruit more runners. He selects 35 random track meets and 40 random soccer games and records if Walpole won. Then, he compares the difference of the win rates. What test should he use?
2 sample t-test for difference of means
The test to determine if the proportion all high school students who have their license is below 0.3 concludes to fail to reject the null hypothesis, p = 0.3, but the true proportion of high school students who have their license is below 0.3.
What value is being interpreted?
Type II error
Sawyer takes a sample of 50 students from the senior class to figure out if the proportion of seniors who are going into trades is greater than 0.10.
Random is not met
The two calculator functions for basic probability (spelled out, no need for pdf or cdf)
geomet AND binom
The df for a t-test or interval is (n-2)
False (n-1)
Finn believes that hours playing coolmathgames in class has a positive association with grade. He randomly selects 45 students in the school from a list and secretly downloads a tracker on their Chromebooks to see their hours on coolmathgames.com and grade. What type of test should be used to confirm or deny his belief.
Linear regression t-test for β
For every increase of 1 mg of pigment, the predicted value of saturation within the acrylic paint tubes increases by about 2.67.
What value is being interpreted?
Slope
Ramu attempts to find out if the proportion of Walpole residents who like jimmy's pizza is greater than 0.1. to do so he takes a random sample of 70 people who live in the town.
Expected counts are not greater than 10
The method to find degrees of freedom for t, linear regression and X2 (Homogeneity or Independence)
n-1, n-2, (# of rows -1 ) * (# of columns - 1)
A histogram should be used to find shape
False
Cole wants to know if the distribution of AP statistics test scores is the same this year as it was last year. 200 random scores from each year are recorded and sorted into categories from 1-5.
Χ2 test for goodness of fit
Assuming Ho:t = 10.7, through many many samples of 15 soccer balls measured for PSI, a t-value of 1.73 or more extreme will occur about 0.0528 of the time.
p-value
Will went to his local supermarket to estimate the true population proportion of pre-shucked corn out of all corn at the market. For this test he takes 30 of the 310 total heads of pre-shucked corn, and produces the interval.
He takes a sample of pre shucked corn, instead of all corn at the market so he can find the proportion.
To be included in the "Choose" category along with hypothesis and procedure when running a t or z test/interval
Parameters
An Employee at the Magners factory in Dublin, Ireland created the t-test
False (He was a Guiness employee)