Question

average annual precipitation by state
louisiana - 59.2 inches
florida - 54.7 inches
hawaii - 50.3 inches
washington - 38.7 inches
california - 23.0 inches
nevada - 9.5 inches
arizona - 11.8 inches
a. what is the independent variable?
b. what is the dependent variable?
c. what is the average rainfall in these states?

Explanation:

Part A: Independent Variable

The independent variable is the one that is manipulated or is the cause, here it's the state (as we're looking at precipitation per state, states are the category we're grouping by, and they don't depend on precipitation).

The dependent variable depends on the independent variable. Here, average annual precipitation depends on the state (different states have different precipitations), so it's the measured quantity based on the state.

Step1: Identify values and count

Values: 59.2, 54.7, 50.3, 38.7, 23.0, 09.5 (which is 9.5), 11.8. Number of states $n = 7$.

Step2: Sum the values

$59.2+54.7 = 113.9$; $113.9+50.3 = 164.2$; $164.2+38.7 = 202.9$; $202.9+23.0 = 225.9$; $225.9+9.5 = 235.4$; $235.4+11.8 = 247.2$

Step3: Calculate average

$\bar{x}=\frac{247.2}{7}\approx35.31$ (rounded to two decimal places)

Answer:

State

Part B: Dependent Variable