3. Describing Data Numerically

Finding the Mean of a Frequency Distribution In Exercises 49–52, approximate the mean of the frequency distribution.

Social Media The average daily amounts of time (in minutes) spent on Snapchat

Cloud Seeding The “Florida Area Cumulus Experiment” was conducted by using silver iodide to seed clouds with the objective of increasing rainfall. For the purposes of this exercise, let the daily amounts of rainfall be represented by units of rnfl. (The actual rainfall amounts are in or )

Find the value of the following statistics and include appropriate units based on rnfl as the unit of measurement.

15.53 7.27 7.45 10.39 4.70 4.50 3.44 5.70 8.24 7.30 4.05 4.46

a. mean

b. median

Given the data set $\{10,12,14,16,18\}$, what is the mean absolute deviation?

Which of the following statements correctly describes the mean salary of all female workers if it is $35000$?

Constructing a Confidence Interval In Exercises 25–28, use the data set to (a) find the sample mean. Assume the population is normally distributed.

Homework The weekly time spent (in hours) on homework for 18 randomly selected high school students

Given the household saving rates: $8$, $12$, $10$, $15$, and $5$, what is the mean of these rates?

Extending Concepts

Trimmed Mean To find the 10% trimmed mean of a data set, order the data, delete the lowest 10% of the entries and the highest 10% of the entries, and find the mean of the remaining entries.

a. Find the 10% trimmed mean for the data in Exercise 65.

Which of the following formulas is the easiest way to calculate the mean of a binomial distribution?

The $\mathrm{sample}\mathrm{mean}$ is the best point estimate of the population mean.

Given forecast errors of $4$, $8$, and $-3$, what is the mean absolute deviation?

Suppose a population consists of the values $1$, $8$, $5$, and $6$. What is the population mean?

Suppose the probability density function is $f\left(x\right)=\frac{1}{2}$ for $0<x<2$. Which of the following statements is true about the median of $x$?