Ch 1: Data & Statistics
Ch 3: Descriptive Statistics, Variability
Ch 3: Z-Score, Empirical, Chebyshev's
Ch 3: Boxplots
Ch 6: Normal Probability Model
100
facts and figures that are transformed into information
What is data?
100
=QUARTILE.EXC(____,3) - QUARTILE.EXC(____,1)
What is the Excel function for calculating IQR?
100
= (x - μ) / σ
What is z-score?
100
The percentage of values that lie between Q1 & Q3
What is 50%?
100
The general Excel function used to calculate probabilities given x (from a normal distribution)
What is "=NORM.S.DIST()"?
200
Descriptive, inferential
What are the two types of statistics?
200
square root of the variance
What is standard deviation?
200
According to this, approximately 68% of values (in a normal distribution) are within one standard deviation of the mean.
What is the Empirical Rule?
200
(Skewness?)
What is a skewed right boxplot?
200
A health expert believes that American adults sleep an average of 6.2 hours on weekdays with a standard deviation of 1.2 hours. Assume that sleep time on weekdays follows a normal distribution. What is the probability that a randomly selected American adult sleeps more than 8 hours on weekdays?
What is 6.7%?
300
Type of categorical/qualitative data; there is a relationship b/t the levels
What is ordinal data?
300
(Modality)
What is a bimodal histogram/distribution?
300
The distribution of a monthly utility bill of a 3 bedroom house using gas or electric energy has mean = $97 and standard deviation = $12. What percentage of homes have a monthly bill b/t $61 and $133?
What is "at least 88.89% of homes have a monthly bill b/t $61 and $133"?
300
(Skewness?)
What is a skewed left boxplot?
300
The flight times from LAX to New York are normally distributed. The average flight time is 325 minutes. The standard deviation is 20 minutes. What is the probability that a random flight takes between 315 to 350 minutes?
What is 58.58%?
400
Type of sampling error; one subset of the population has no chance, less of a chance, or more of a chance of being chosen
What is selection bias?
400
= standard deviation/mean * 100%
What is the coefficient of variation (CV)?
400
The distribution of a monthly utility bill of a 3 bedroom house using gas or electric energy has mean = $97 and standard deviation = $12. The distribution is mound-shaped and symmetric. What percentage of homes have a monthly bill > $121?
What is "2.5% of homes have a monthly bill > 121"?
400
The test scores of 20 students are summarized by the five-number summary below:
Minimum = 42
Q1 = 55
Median = 68
Q3 = 80
Maximum = 95
What are the lower & upper limits (for determining outliers)?
What is the "Lower Limit = 17.5"?
What is the "Upper Limit = 117.5"?
400
The mean daily studying time for ISDS 361A is 5 hours, with a standard deviation of 1.2 hours. Suppose the daily studying time is normally distributed. If I study for more hours than 80% of ISDS 361A students, at least how many hours am I studying per day?
What is 6.01 hours?
500
Suppose that a company that sells an in-bed basinet for co-sleeping parents want to determine whether there may be interest in their product. Co-sleeping is the act of placing a baby (with the proper barriers) onto the same bed as one or more parents sleep rather than in their own place like a crib or a basinet. To help make their decision, they ask 10 individuals with kids that work there whether they decided to co-sleep or not.
Based on the information given, "The parameter of interest"
What is the proportion of co-sleeping parents that would be interested in their product (in-bed basinet)?
500
(Symmetry, skewness, modality)
What is a non-symmetrical, skewed right, unimodal histogram?
500
The average daily water consumption in a city is 250 liters with a standard deviation of 20 liters. The distribution is skewed right. What percentage of observations are within 4 standard deviations of the mean?
What is "At least 93.75% of observations are within 4 SD of the mean"?
500
The 5 Number Summary (List it out)
What is "Q0, Q1, Q2, Q3, Q4"
or "0th, 25th, 50th, 75th, 100th Percentile"
or "Minimum, Q1, Median, Q3, Maximum"?
500
The average commute time to campus for ISDS 361A students is 35 minutes, with a standard deviation of 6 minutes. Suppose commute times are normally distributed. If a student's commute is shorter than 10% of ISDS 361A students, what is their commute time?
What is 27.31 minutes?