Chp 3 Quiz STA 2023 McGraw-Hill

Professors at a local university earn an average salary of $80,000 with a standard deviation of $6,000. With the beginning of the next academic year, all professors will get a 2% raise. What will be the average and the standard deviation of their new salaries?

$81,600 and $6,120.

The following data represent monthly returns (in percent): -7.24 1.64 3.48 -2.49 9.30 The geometric mean return is the closest to ________.

0.78% The geometric mean return is defined as formula18.mml Wrong answers include arithmetic mean, median, using positive values of growth rates instead of negative ones, and not converting percentages to fractions.

Sales for Adidas grew at a rate of 0.5196 in 2006, 0.0213 in 2007, 0.0485 in 2008, and -0.0387 in 2009. The average growth rate for Adidas during these four years is the closest to _______.

11.83% Use growth rate formula (Long one)

The price to earnings ratio, also called the P/E ratio of a stock, is a measure of the price of a share relative to the annual net income per share earned by the firm. Suppose the P/Es for a firm's common stock during the past four quarters are 10, 12, 15, and 11, respectively. The standard deviation of the P/E ratio over the four quarters is ______.

2.16

The sample data below shows the number of hours spent by five students over the weekend to prepare for Monday's Business Statistics exam. 3 12 2 3 5. The interquartile range of the data is the closest to ________.

6 hours The interquartile range is computed as a difference L75 - L25.

Automobiles traveling on a road with a posted speed limit of 65 miles per hour are checked for speed by a state police radar system. The following is a frequency distribution of speeds. The standard deviation of this distribution is closest to

6.81

In its standard form, Chebyshev's theorem provides a lower bound on __________________________________

the proportion (or percentage) of observations lying within a certain interval

The _______ identifies the number of standard deviations a particular value is from the mean of its distribution.

z-score The z-score measures the distance of a given sample value from the mean in standard deviations.

Which of the following relationships can be concluded from examining the correlation coefficient?

All of the Above positive relationship negative relationship no relationship

In a marketing class of 60 students, the mean and the standard deviation of scores was 70 and 5, respectively. Use Chebyshev's theorem to determine the number of students who scored less than 60 or more than 80.

At most 15 According to Chebyshev's theorem, for any data set, the proportion of observations that lie within k standard deviations from the mean is at least 1 - 1 / k2. If k = 2, at least 75% of the observations fall in the interval defined by formula54.mml

What is(are) the characteristic(s) of the coefficient of variation?

Both it adjusts for differences in the magnitude of means and it allows for direct comparisons across different data sets.

Geometric mean is greater than arithmetic mean

False Geometric mean is smaller than arithmetic and more sensitive to outliers

The variance and standard deviation are the most widely used measures of central location.

False The variance and standard deviation are the most widely used measures of dispersion

Which of the following statements about the mean absolute deviation (MAD) is themost accurate?

It is denominated in the same units as the original data. The sample mean absolute deviation is formula21.mml the population mean absolute deviation is formula22.mml

The formula for a z-score is 11formula11.mml

True x-xbar/s

The variance is the arithmetic mean of the squared deviations from the mean.

True (look at variance formula)

In a data set, an outlier is a large or small value regarded as an extreme value in the data set.

True

Professors at a local university earn an average salary of $80,000 with a standard deviation of $6,000. The salary distribution is approximately bell-shaped. What can be said about the percentage of salaries that are at least $74,000?

about 84% Since the data are bell-shaped, we apply the Empirical Rule. According to the Empirical Rule, approximately 68% of the salaries will lie within one standard deviation of the mean ($74,000 to $86,000). Therefore, half of these salaries (34%) will lie between $74,000 and $80,000. Since 50% of salaries will lie above $80,000, this means 34% + 50% = 84% will be at least $74,000.