Exam 3: Numerical Descriptive Measures

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:

Calculate the interquartile range from the following data: 1,2,4,5,10,12,18.

When applicable,the empirical rule provides the approximate percentage of observations that fall within how many standard deviations from the mean?

The Boom company has recently decided to raise the salaries of all employees by 10 percent.Which of the following is (are)expected to be affected by this raise?

Consider a population with data values of . The population standard deviation is closest to:

A college professor collected data on the number of hours spent by his 100 students over the weekend to prepare for Monday's Business Statistics exam.He processed the data by Excel and the following incomplete output is available. The coefficient of variation in the data is

The advantage of using mean absolute deviation rather than variance as a measure of dispersion is that mean absolute deviation:

Professors at a local university earn an average salary of $80,000 with a standard deviation of $6,000.The salary distribution cannot be regarded as bell-shaped.What can be said about the percentage of salaries that are less than $68,000 or more than or more than $92,000?

What is the difference between Chebyshev's theorem and the empirical rule?

Amounts spent by a sample of 200 customers at a retail store are summarized in the following relative frequency distribution. The mean amount spent by customers is closest to:

A surfer visited his favorite beach 50 times and recorded the wave height each time in the following table. a.Calculate the average wave height. B)Calculate the variance and standard deviation wave height for this sample.

Consider a population with data values of . The mode is:

The mean grade of the 30 students in Section 1 is 80.The mean grade of the 40 students in Section 2 is 85.The mean grade of the 30 students in Section 3 is 80.What is the mean grade of all students from the three sections combined?

Amounts spent by a sample of 50 customers at a retail store are summarized in the following relative frequency distribution. The mean amount spent by customers is closest to:

The variance is an average squared deviation from the mean.

The covariance between the returns on two assets is negative.This occurs when:

Chebyshev's theorem is only applicable for sample data.

When interpreting the covariance between variables x and y,which of the following statements is most accurate?

Yearly returns (rounded to the nearest percent)for GLD a gold exchange traded fund and SLV a silver exchange traded fund are reported in the following table. a.Calculate the covariance between GLD and SLV. B)Calculate and interpret the correlation coefficient.

The median is not always the 50^th percentile.