Probability, Random Variables, and Probability Distributions
If the weights of pumpkins in a patch are normally distributed with a mean of 10 pounds and a standard deviation of 2 pounds, what would be the new standard deviation if we were to quadruple every pumpkin's weight?
8 pounds
4 pounds
Cannot be determined without additional information
2 pounds
What would be the standard deviation for the discrete random variable representing flipping a fair coin three times and counting heads?
What does the standard deviation of a random variable measure?
The sum of all the values in the distribution.
The difference between the maximum and minimum values.
The probability of a specific outcome.
The spread or variability of the values.
What kind of study involves observing subjects without influencing them?
Experimental study
Observational study
Theoretical simulation
Content analysis
In a set containing x data points whose values range from minimum value to maximum value , using standardized score transformation ext{SSC} = rac{x_i - x_{ ext{min}}}{x_{ ext{max}} - x_{ ext{min}}}, what would SSC be for a point exactly halfway between the min and max?
.70
.75
.50
.25
What does the Central Limit Theorem state?
The sample size must be large for hypothesis testing.
The mean of a distribution equals its standard deviation.
The sample mean is normally distributed.
The standard deviation increases with the sample size.
A store owner records sales in dollars from Monday through Friday with values 120, 110, and $ 130 respectively; what's their approximate combined mean and standard deviation?
18
17
20
19

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A school survey asks students to rate their satisfaction with lunch options on a scale of –10. When analyzing the data, they find the responses are modeled by a symmetric bell-shaped curve centered at a rating of 0. Which of the following describes the relationship between the median and the average ratings?
Not enough information to determine the relation
Median less than Average
Median greater than Average
Median equal Average
What is the mean of a discrete random variable X that takes on values 2, 4, and 6 with probabilities 0.2, 0.5, and 0.3 respectively?
A game show contestant can either win 200 when spinning a wheel depending on where it lands; given that both outcomes are equally likely, what is this game's expected payoff?
-$350
$150
$650
$300