Organizing Data
This type of random variable requires a fixed number of trials, independent trials, and binary.
What is a binomial random variable?
Do experienced computer-game players earn higher scores when they play with someone present to cheer them on or when they play alone? Fifty teenagers with experience playing a particular computer game have volunteered for a study. We randomly assign 25 of them to play the game alone and the other 25 to play the game with a supporter present. Each player’s score is recorded.
What is Two Sample T Test for Means?
If a basketball player makes 3 out of every 4 free throws, what is the probability that he will make 6 out of 10 free throws in a game?
binompdf(n:10,p:3/4,x:6)=0.1460
Are male college students more likely to binge drink than female college students? The Harvard School of Public Health surveys random samples of male and female undergraduates at four-year colleges and universities about whether they have engaged in binge drinking. What type of Inference method is this?
Two sample z test for proportion
What are the equations we use to calculate for outliers?
Upper: Q3+1.5*IQR
Lower: Q1-1.5*IQR
You better remember this!
Events that have no outcomes in common and can never occur simultaneously, for which the addition rule is used.
What are mutually exclusive events)?
Drowning in bathtubs is a major cause of death in children less than 5 years old. A random sample of parents was asked many questions related to bathtub safety. Overall, 85% of the sample said they used baby bathtubs for infants. Estimate the percent of all parents of young children who use baby bathtubs.
What is the one sample z interval for proportions?
The Interquartile Range!!! (IQR= Q3-Q1)
What is the correlation coefficient of the linear regression if the coefficient of determination, r2 , is 0.64?
squareroot(0.64)= 0.8
The correlation coefficient is 0.8, meaning we have a strong correlation between the variables x and y.
The 4 basic principles of experimental design.
What are control, randomize, and replicate and comparison?
Augustus draws tickets one at a time for a raffle. The person named on the ticket must be present to win, but 30% of the 750 raffle tickets have the names of people who are not present. Let T be the number of tickets Augustus needs to draw to find a winner who is present.
Find the probability that Augustus first draws the name of someone present on the 3rd ticket.
geometpdf(p:0.70,x:3)=0.063
Three conditions are to be verified for inference about a proportion.
What are the population size be greater than or equal to 10n and n times p hat & n times (1 - p hat) be greater than or equal to 10, Must be random SRS or randomly assigned, and the sample size must be less than 10% of the population.
This calculator command can be used to find the area under a normal distribution and ABOCE/BELOW an interval.
What is normalcdf?
A least-squares regression line for predicting the weights of basketball players based on their heights produced the residual plot below. What does the residual plot tell you about the linear model if the graph shows a curved pattern?
The curved pattern in the residual plot suggests that the linear model is not appropriate for this graph. Perhaps a quadratic model will be best for this particular problem.
Describe how you would randomly assign a placebo and low-dose aspirin to three different female age groups(24-32 year olds, 35-40 year olds and 50-70 year olds). (*Cough* *Cough* Oasis)
Block the female patients in three different age groups, 24-32, 35-40, and 50-70 year olds. Give every single one of the patients in the 24-32 group a unique number and using an RNG select the patients who will be receiving the placebo and the other half will be implemented with the low-dose aspirin. Repeat the same instructions for the rest of the groups, collect data, and make conclusions about the findings.
Mason never has a pencil when test day rolls around. Because the classmates are tired of having to supply pencils for Mason, only 15% of students will give Mason a pencil when asked. Today is test day and Mason begins asking randomly selected students for a pencil. Let Y = the number of students Mason asks until he finds someone who will give him a pencil.
Should Mason be surprised if Mason did not receive a pencil until he asked at least 10 people? Calculate the probability to justify the answer...
p(x>or equal to 10)= 1- geometCDF(p:0.15,x=9)=0.2316
x +/- t*Sx
What is the confidence interval for estimating the true parameter of a sample mean?