Characteristics of Data
Percentiles
Dispersion, Standard Deviation & Z-scores
Sampling Distribution and CLT
Potpourri
100
Continuous data is countable. True or False?
False. Discrete is countable. Continuous has an infinite number of possible data points in an interval.
100
This is the 50th percentile
Median
100
The denominator (n-1) in the calculation of sample variance is called what?
degrees of freedom
100
This would be considered an example of the underestimation or overestimation of mu, a parameter.
Bias
100
66 million years ago, the asteroid that wiped out most of the dinosaurs on earth led to this many days of darkness.
approx. 650 to 700 days of darkness
200
______________ data is non-numeric in its original state, while ___________ data is numeric.
Qualitative, Quantitative
200
The _______ is sensitive to outliers - and the ________ is a remedy for that
Mean, Median
200
Another term for scaling down raw data to a universal scale of numbers
standardizing
200
We can say the sampling distribution of sample means is normal if what is normal?
The population distribution that the samples come from
200
This past May, this beer replaced Bud Light as leader in U.S. sales.
Modelo Especial
300
Date of Birth.
N, O, I, R?
Interval. "Zero" has meaning as somebody could have been born in Year "0".
300
In finding the value for a respective percentile, this is the 1st step to perform.
Order the values - ascending
300
Why are the error terms squared before summing them vs. after?
If you summed the error terms before summing them they would approximate zero. Zero would mean no dispersion.
300
This is a measurement taken on sample
Statistic (examples: x-bar, s, p-bar, median)
300
A man dies of old age on his 25 birthday. How is this possible?
His birthday was on February 29th.
400
Amount of data left on your monthly plan if you don't have an unlimited data package.
Discrete or Continuous?
Continuous.
Even though it may say you have 0.75 GB of data remaining, you really have an amount between 0.74 and 0.76. True amount of data left could be an infinite amount of possibilities between 0.74 and 0.76. Which makes it continuous.
400
This is another term for the 75th percentile
Q3
400
What is the z-score of a data point with a value of 3, given the below?
x-bar = 6
s^2 = 9
z = -1
z =
(3 - 6) / (9^.5)
400
The sampling distribution of sample means that is selected from a skewed distribution can only be assumed normal if, at least, this number of samples are taken
30
400
The U.S. military rented out their F-18 at this approximate cost each - for last summer's blockbuster movie.
Name the cost and movie.
$11,000/hr.
Top Gun: Maverick
500
This type of visualization comes about by filling bins/buckets with observations/data
Histogram
500
Q1: 12
Q2: 18
Q3: 22
IQR: ?
10
IQR = Q3 - Q1 = 22 - 12
= 10
500
Using the empirical rule, what is the probability between z-scores of -2 and 0?
47.5% from 34 + 16 - 2.5
between -1 and 0 is 34%
less than -1 is 16%
less than -2 is 2.5%
500
Is the roll of a dice an example of a continuous or discrete uniform distribution?
Discrete. Cannot have an infinite number of values rolled between then interval 1 and 2, 2 and 3, 3 and 4, etc.
500
In early 2023, this company lost over $250B of its value. It was the single largest one-day loss for a company in U.S. history.
What company was this?
More importantly, what caused such a destruction in value?
Facebook.
Apple's Privacy Notice (ATT) in summer 2022 meant that Facebook and other social media companies (SNAP, etc) could no longer track the cookies (digital drooling) of iPhone users. As a result Facebook revenues fell almost $10B dollars from the previous year.