Percentiles
Z Scores
Linear Transformations
Empirical Rule
Normal Curve Calculations
100
If I tell you that you scored at the 55th percentile on your final exam, you would know that...
55% of the class scored the same or worse than you did
OR
You scored the same or better than 55% of the class.
100
What is the formula to find the z-score of a data point?
z = (x - μ ) / σ
100
This feature of a distribution stays the same no matter what linear transformation is applied to the data set.
Shape
100
Another name for the empirical rule is...
The 68-95-99.7 Rule
100
What is a name of the calculator function used to find the area under a normal curve?
normalcdf
200
The 75th percentile is also know as the
median
200
Name at least one college/university that Ms. Tenace has attended. You will receive 200 points per correct answer.
Boston University
FIT (Fashion Institute of Technology)
ASU
Trident University
200
If you standardize all values in a distribution, what would the new mean and standard deviation be?
Mean: 0
SD: 1
200
What percent of data is within 1 standard deviation from the mean?
68%
200
On a website that has brain games and cognitive tests, the distribution of reaction times for a certain clicking task follows an approximately normal distribution with a mean of 284 milliseconds and a standard deviation of 50 milliseconds.
What percent of people take longer that 300 milliseconds to complete the task?
37.45%
300
Given the data set: 1, 2, 3, 6, 9, 11, 45, 102, calculate the percentile rank for 11.
75th percentile
300
Rebecca performs improv comedy. Rebecca's funniness factor at her last performance had a z-score of 2.76. Interpret Rebecca's z-score.
Rebecca's funniness factor was 2.76 standard deviations above the mean.
300
The distribution of raw scores on a particular achievement test has a mean of 500 and a standard deviation of 80.
If each score is increased by 25, what will be the mean and standard deviation of the distribution of new scores?
Mean: 525
SD: 80
300
What percent of data is greater than 3 standard deviations away from the mean?
0.3%
300
Name Ms. Tenace's two cats. Earn 300 points for each correct answer.
Ozzy and Gat (Strigata)
400
DAILY DOUBLE!
What is Ms. Tenace's birthday?
August 13th
400
What does the shaded part of this normal distribution graph represent?
All data that is one or more standard deviations above the mean.
400
Ms. Tenace measured the IQ of her algebra 2 students and found that the mean IQ of all her classes was 82. Ms. Tenace wants to display this data in terms of brainyness points rather than IQ as to not offend some students. One IQ point is worth 3.5 brainyness points. What is the new mean of Ms. Tenace's algebra 2 students once IQ has been converted to brainyness points?
287
400
The height of plants in a certain garden are normally distributed with a mean of 28 inches and a standard deviation of 5.9 inches.
Use the Empirical Rule to estimate what percentage of plants are greater than 22.1 inches tall.
84%
400
For a certain online store, the distribution of number of purchases per hour is approximately normal with mean 1200 purchases and standard deviation 200 purchases. About what number of purchases does the store need to make in an hour to be in the top 16% of hours?
About 1400.
500
The percentile represents the...
percent of data values that are below.
500
At a local high school, GPAs are normally distributed with a mean of 2.9 and standard deviation of 0.6. What is the z-score for the 80th percentile?
0.84
500
DAILY DOUBLE!
You have 2 minutes to write a joke. If Ms. Tenace laughs at the joke, you earn 1000 points.
Did Ms. Tenace laugh?
500
What does it mean to be facetious?
To be annoying on purpose.
Being humorous in inappropriate situations.
Making jokes to get attention.
500
The distribution of lengths of salmon from a certain river is approximatel normal with standard deviation 3.5 inches. If 10 percent of salmon are longer than 30 inches, what is the mean of the distribution?
25.5 inches. Will accept 26 or other close roundings.