MAT 150 - STATS - Midterm Exam
2022/2023
T/F: The trimmed mean is a measure of variation of a dataset - ANS- False
T/F: To compute the z-score for a normally distributed data set, you would need the
observation, the
...
MAT 150 - STATS - Midterm Exam
2022/2023
T/F: The trimmed mean is a measure of variation of a dataset - ANS- False
T/F: To compute the z-score for a normally distributed data set, you would need the
observation, the mean, and the interquartile range - ANS- False
T/F: The Empirical Rule gives the approximate percentage of observations about the
mean of a data set for uniformly distributed data - ANS- False
T/F: The variance is the square of the standard deviation - ANS- True
The x = the amount of energy generated by a solar panel in a year (in kWh). If you
were to compute the variance of a random sample of solar panels, what would the
units be? - ANS- s^2 = kWh^2
The standard normal (z) distribution has a mean of ______ and a standard deviation
of _______ - ANS- 0....1
For a data set that is left skewed, which has a better measure of center - the mean
or the median? - ANS- median
Let z denote a variable that has standard normal distribution. Determine the
following: P (1.95 < z < 2.75) = - ANS- 0.0226
Let z denote a variable that has a standard normal distribution. Determine the
following: P (z > -1.95 or z > 2.72) = - ANS- 0.0289
Let z denote a variable that has a standard normal distribution. Find z* such that: P
(z < z*) = 0.95 - ANS- 1.65
The World Health Organization reports that the distribution of ages at time of death
in the United States has a mean of 79.8 years and a standard deviation of 15.5
years, based on death certificates. The distribution of ages at the time of death if leftskewed, as few people die young and most die old. Researchers plan to take a
random sample of 80 American death certificates. What is the probability that the
mean age at the time of death in a random sample of 80 American death certificates
will be less than 78 years? Include notation and draw and label the appropriate
distribution curve. CONTINUES...
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