Chapter 7
The ________ variable goes on the X-axis.
Explanatory
What is it called to predict outside of existing x values?
Extrapolation
The individuals we have interest in learning about. We take samples from this.
Population
In a school, 40% of students play a sport, 35% are in a club, and 25% do neither. If you randomly select 4 students, what is the probability that all of them do not participate in a sport or a club?
0.0039
What are the odds that when you flip a coin it will land on tails 9 straight times?
0.00195
What are the 4 conditions for regression?
2 Quantitative Variables, Does the plot thicken?, No Outlier, Straight Enough
What is the variable that can create a false correlation between an x and a y?
Lurking Variable
"Do you agree that our university provides excellent student resources and should receive more funding to continue these great services?" What is the type of bias?
Response Bias
A company survey shows that 60% of employees prefer remote work, 30% prefer hybrid, and 10% prefer in-office only. If 3 employees are randomly selected, what is the probability that all of them prefer in-office or hybrid work?
0.064
A deck of 52 playing cards contains 13 spades, 13 hearts, 13 diamonds, and 13 clubs. If you randomly draw one card, what is the probability that it is either a heart or a diamond?
0.5
A study finds that the monthly car payment for a person can be estimated using the formula:
Car Payment=150+0.02×Annual Income
What would be the car payment for someone with an annual income of $51,205?
$1,174.10
What value of p normally indicates that the association is due to random chance?
0.05 or greater
A company wants to survey its employees about job satisfaction. The HR department has a list of 1,000 employees and decides to survey every 10th employee on the list.
What type of sampling is this?
A: It is snowing outside
B: School is cancelled
Are these events independent? Are they disjoint?
Not independent and not disjoint
A secret agent must pass through three security checkpoints. Each checkpoint has a 75% chance of letting them through without setting off an alarm. What is the probability that the agent makes it through all three checkpoints undetected?
0.422
A regression model predicts the price of a used car using the following formula:
Predicted Price=5,000+2.5×Age
If a 4-year-old car actually sells for $14,000, what is the residual for this prediction?
-8,990
Monthly Rent=500+2.75×Square Feet
Interpret the Y-Intercept
If the square footage of an apartment is 0 feet, then the monthly rent will be $500.
A school wants to survey students about their study habits. The student population is divided into four grade levels: Freshmen, Sophomores, Juniors, and Seniors. The researchers randomly selected 50 students from each grade level to participate in the survey. What sampling strategy is this?
Stratified
We are drawing 5 cards from 5 different decks, each containing 20 cards: 8 spades, 5 diamonds, 4 hearts, and 3 clubs. What is the probability of drawing a heart, then a club, then a spade, then a diamond, and then a heart again?
0.0006
A comic book store is giving away 10 random superhero action figures: 4 Spider-Man, 3 Batman, and 3 Iron Man. If you randomly pick 3 figures, what is the probability that you get at least one Spider-Man?
0.784
Test Score=50+3.2×Hours Studied
Interpret the slope
For every hour increase studying, we can expect a student's test score to increase by 3.2 points on average.
Calories Burned=100+8.5×Minutes of Exercise
If R^2 is 0.856, interpret the R^2 value.
85.6% of the variation in Calories Burned is explained by the variation in Minutes of Exercise.
A university wants to determine what percentage of engineering students use the campus tutoring center. A survey is emailed to all students enrolled in ENGR 101, 201, 305, and 410.
Population?
Parameter of interest?
Sampling frame?
Sample?
Sample method?
Engineering students; Percent of engineering students who use the campus tutoring center; All students enrolled in ENGR 101, 201, 305, and 410; Students who responded to the survey; Voluntary response sampling
A box contains 10 red balls, 8 blue balls, and 6 green balls. You randomly draw 4 balls with replacement. What is the probability that you draw at least one red ball?
0.8842
A treasure chest contains 12 gems: 4 rubies, 5 sapphires, and 3 emeralds. You randomly pick 4 gems with replacement. What is the probability that you get at least one thing that is not an emerald?
0.996