Probability, Random Variables, and Probability Distributions
If it's known that after five patients were treated without reaction to a new medication, there was an approximately 10% chance that this could occur under normal conditions, what's implied about the single-trial reaction rate?
(five successes) ≈ 20%, (one-trial success rate + p)
P(five successes) = (one-trial success rate)^5 = 10%, one-trial success rate ≈ 20%
(five successes) = n(p+q), (one-trial success rate, p, q = probability of failure) ≈ 20%
(five successes) = np, (one-trial success rate, p, n = number of trials) ≈ 20%
Which function is used to calculate the probability of a geometric random variable Y being equal to a specific value k?
Cumulative distribution function (CDF).
Probability mass function (PMF).
Mean and standard deviation.
Probability density function (PDF).
If a player free-throw shooter succeeds % but misses several times in a row during a game, would this imply anything about their true shot-making skill level?
Potentially learned opponents' defensive strategies and have adapted
Maybe affected by temporary factors like fatigue or pressure
Yes, implies a decrease in overall ability
No, random variations exist independently of past performance
When researching consumer behavior patterns, if an analyst estimates that customers make purchases on average once every eight visits to an online store, what is the probability that a purchase will occur on any given visit?
0.124
0.122
0.125
0.127
A car salesperson sells cars at a rate where about fifteen percent are returned within thirty days due to buyer remorse. If she sells eight cars in January, what is the likelihood that exactly none come back?
Eighty-five percent raised to the eighth power, nearly seventy-two hundredths percent
Fifteen percent raised to the eighth power or roughly forty-three hundredths percent
Fifteen percent raised to the seventh power, around twenty-five percent
One minus fifteen percent raised to the seventh power, approximately eighty-five percent
If a geometric random variable has a probability of success of 0.3 on each trial, what is the probability of needing exactly 5 trials to achieve the first success?
What would you expect from many repetitions when considering an experiment following geometric distribution with ?
On average one failure before seeing one success.
Each trail have equal and independent chances at being successful.
An increasing chance of success with more trials done.
Average two trials until seeing the first success.

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What is the probability that a test will require more than 10 components to be tested before detecting a defect, given that the probability of a component failure is set at 0.111?
0.6847
0.07383
0.101
0.2645
0.3487
What is the expected value of trials needed for a basketball player with a free throw success rate of to make her first basket?
np = n(1/5), where n is an integer.
What is the possible range of values for a geometric random variable?
All positive integers.
All non-negative integers.
All real numbers.
All natural numbers.