STAT 201 Final Exam Questions With
Correct Answers
Discrete vs. Continuous discrete random variable X takes a set of
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separate values while a continuous random variable has its possible
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values form an interval - CORRECT ANSWER✔✔-discrete random
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variable X takes a set of separate values while a continuous random
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variable has its possible values form an interval
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Definition of Expected Value - CORRECT ANSWER✔✔-the mean µ of the
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probability distribution of a random variable x = E[X]
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Definition of Variance - CORRECT ANSWER✔✔-weighted average of its
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squared distances from the mean µ
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Binomial Mean/SD - CORRECT ANSWER✔✔-Mean=np, SD
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sigma=sqrt(np(1-p))
Probabilities of a binomial distribution - CORRECT ANSWER✔✔-With
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probability of success p, number of trials n, and number of successes x
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P(x)=(n!)/(x!(n-x)!) multiplied to p^(x)(1-p)^(n-x) | | |
, Conditions for binomial distribution - CORRECT ANSWER✔✔-Binary
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data, random sampling, independence between trials
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Sampling Distribution - CORRECT ANSWER✔✔-The probability
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distribution that specifies probabilities for the possible values a statistic
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can take
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Mean/SD of the sampling distribution of the population proportion -
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CORRECT ANSWER✔✔-Mean=p, sd= sqrt(p(1-p)/n); will replace p with
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phat so sd becomes standard error
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Mean/SD of the sampling distribution of the sample mean - CORRECT
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ANSWER✔✔-Mean mu, sd sigma/srt(n); will replace sigma with | | | | | | |
s/sqrt(n), which becomes standard error
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95% confidence interval for a population proportion - CORRECT
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ANSWER✔✔-phat + or - 1.96(se) | | | |
Curse of the square root sign - CORRECT ANSWER✔✔-Margin of error
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z(se)=zsqrt(phat(1-phat)/n); to halve margin of error, you can't double n, | | | | | | | | |
you have to quadruple n.
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Correct Answers
Discrete vs. Continuous discrete random variable X takes a set of
| | | | | | | | | | |
separate values while a continuous random variable has its possible
| | | | | | | | | |
values form an interval - CORRECT ANSWER✔✔-discrete random
| | | | | | | |
variable X takes a set of separate values while a continuous random
| | | | | | | | | | | |
variable has its possible values form an interval
| | | | | | |
Definition of Expected Value - CORRECT ANSWER✔✔-the mean µ of the
| | | | | | | | | | |
probability distribution of a random variable x = E[X]
| | | | | | | |
Definition of Variance - CORRECT ANSWER✔✔-weighted average of its
| | | | | | | | |
squared distances from the mean µ
| | | | |
Binomial Mean/SD - CORRECT ANSWER✔✔-Mean=np, SD
| | | | | |
sigma=sqrt(np(1-p))
Probabilities of a binomial distribution - CORRECT ANSWER✔✔-With
| | | | | | | |
probability of success p, number of trials n, and number of successes x
| | | | | | | | | | | |
P(x)=(n!)/(x!(n-x)!) multiplied to p^(x)(1-p)^(n-x) | | |
, Conditions for binomial distribution - CORRECT ANSWER✔✔-Binary
| | | | | | |
data, random sampling, independence between trials
| | | | |
Sampling Distribution - CORRECT ANSWER✔✔-The probability
| | | | | |
distribution that specifies probabilities for the possible values a statistic
| | | | | | | | | |
can take
|
Mean/SD of the sampling distribution of the population proportion -
| | | | | | | | | |
CORRECT ANSWER✔✔-Mean=p, sd= sqrt(p(1-p)/n); will replace p with
| | | | | | | |
phat so sd becomes standard error
| | | | |
Mean/SD of the sampling distribution of the sample mean - CORRECT
| | | | | | | | | | |
ANSWER✔✔-Mean mu, sd sigma/srt(n); will replace sigma with | | | | | | |
s/sqrt(n), which becomes standard error
| | | | |
95% confidence interval for a population proportion - CORRECT
| | | | | | | | |
ANSWER✔✔-phat + or - 1.96(se) | | | |
Curse of the square root sign - CORRECT ANSWER✔✔-Margin of error
| | | | | | | | | | |
z(se)=zsqrt(phat(1-phat)/n); to halve margin of error, you can't double n, | | | | | | | | |
you have to quadruple n.
| | | | |
