Statistics Vocab
Normal Distribution
Margin of Error and
Z-Scores
Z-Scores
Conditional & Compound Probability
Independent and Dependent Probability
100
What type of study is this?
You study how grocery shoppers navigate a store and shop differently after a layout change.
Observational Study
100
A line for tickets to a concert had a mean waiting time of 20 minutes with a standard deviation of 4 minutes. What percentage of people waited for more than 28 minutes?
2.5%
100
When 3001 voters were polled, 73% said they were voting “yes” on an initiative measure. Find the margin of error and confidence interval.
Margin of error: 2%
Confidence interval: (71%, 75%)
100
You roll a six-sided dice. Find the probability.
P(5 ∪ Even)=
4/6
100
You flip a fair coin. What is the probability that it shows heads on the first flip and shows tails on the second flip?
1/4
200
What kind of study is this?
In a study to see if administering a medication orally or by injection makes a difference in how quickly people with back pain feel relief, a group of 400 adults suffering from back pain is divided into two groups. One group of 200 people is given the medication in pill form, while the other group of 200 people is given the medication in the form of a shot. Results for each group are compared to see if there is a difference in pain relief between the two methods.
Experiment
200
Speeds of 1,000 cars on a highway were recorded. The mean speed was 70mph with a standard deviation of 5mph. How many cars were going less than 65mph?
160
200
The grades on a geography exam were roughly normally distributed with an average of 78 and standard deviation of 6. Grady scored a 81 on the exam.
Find the z-score for Grady's exam grade. Round to one decimal place as needed.
0.5
200
P(4 | Black)=
2/26
200
Steve reaches into a bag with 5 red marbles, 3 yellow marbles, and 2 green marbles, and randomly selects one. Then, he puts the marble back, and Sam reaches into the same bag and randomly selects a marble. What is the probability that both guys selected a yellow marble?
9/100
300
A sample of 2,000 was sought to estimate the average achievement in science of fifth graders in a city’s public schools. The average fifth grade enrollment in the city’s elementary schools is 100 students. Thus, 20 schools were randomly selected and within each of those schools all fifth graders were tested. What sampling method is being used?
Cluster Sampling
300
The monthly income of 5,000 employees at a certain company is $2,500 with a standard deviation of $250. How many employees earn more than $2,750 per month?
800 employees
300
The grades on a math exam were roughly normally distributed with an average of 83 and standard deviation of 5. Ben scored a 70 on the exam.
Find the z-score for Ben's exam grade. Round to one decimal place as needed.
-2.6
300
P(Over 50 Texts ∩ Age 23-60)
157/456
300
A bowl contains 4 tangerines and 5 clementines. John randomly selects one piece of fruit without putting it back, and then Pam randomly selects one of the remaining pieces of fruit. What is the probability that John selects a tangerine and Pam selects a clementine?
20/72
400
Which does not have bias?
a) A phone-in survey is taken by a radio station to see how many listeners enjoy jazz in the morning.
b) Every forth student who enters the school is asked to name their favorite sport.
c) A shirt manufacturer wants to check quality control of their products. The plant manager decides to check every 5th shirt inspected by Inspector D. There are 15 inspectors in the plant.
b
400
The monthly income of 5,000 employees at a certain company is $2,500 with a standard deviation of $250.What percent of employees earn between $2,000 and $3,000 per month?
95%
400
A survey of 850 people reported that 42% favored the re-election of the current governor. Find the margin of error and confidence interval.
Margin of error: 3%
Confidence interval: (39%, 45%)
400
P(Jack ∪ Red)=
28/52
400
There are 6 pennies, 9 nickels, and 3 dimes in a box. Find the probability of picking a nickel and not putting it back, then picking another nickel.
72/306
500
What sampling method is this?
Your class submits solutions to a problem and your teacher divides the work into four piles by achievement levels. She then randomly picks two examples from each.
Stratified Sampling
500
The mean life of a battery is 50 hours with a standard deviation of 6 hours. The manufacturer says they will refund any batteries that last less than 38 hours. If they produced 50,000 batteries, how many will they expect to refund?
1,250
500
The grades on a statistics exam were roughly normally distributed with an average of 79 and standard deviation of 2. Shane scored a 85 on the exam.
Find the z-score for Shane's exam grade. Round to one decimal place as needed.
3
500
P(Male | Left Handed)=
13/24
500
You are playing a game that involves spinning the money wheel shown. During your turn, you get to spin the wheel twice. What is the probability that you get more than $500 on your first spin and then go bankrupt on your second spin?
16/576