California Water Usage Research Question What factors influence California residence’s daily water usage? Hypotheses H 0 (Null): The independent variables have no statistically significant associations with domestic daily water usage/person (gal.). H A ( Alternative): The independent variables do have statistically significant associations with domestic daily water usage/person (gal.). By Gabby Hernandez, Meme Torio, Kendall Thompson

Sources U.S. Geological Survey Collected from local, state, and federal agencies National Oceanic & Atmospheric Administration Collected from Climatic Weather Stations 2010 U.S. Census Collected by the federal government (US Census Bureau) Sample Size All 58 California Counties Dependent Daily use/Person) gals. Domestic Water Usage (Daily use/Person) gals. Independent Annual Precipitation (in.) Avg. Annual Temp. (F°) Avg. Household Size % of Population w/ BA or higher (25+) % Black or African American % White (non-Hispanic or Latino) % Hispanic or Latino About Our Data

VariableCoefficientsStandard ErrorP-Value Total Precipitation (In.) Mean Annual Temp. (F°) % Black or African American % White (non-Hispanic or Latino) % Hispanic or Latino % of Pop. With BA or higher (25+) Avg. Household Size F-stat6.287Significance F0.000 Adjusted R-square0.394Number of Observations58 At the 95% confidence level the following variables were statistically significant: Total Annual Precipitation, % of CA residents who are White, % of Population w/ BA or Higher (25+), and Average Household Size. Ex: As the percentage of the population (25 and older) with Bachelor’s degrees or higher increases by 1%, daily domestic water usage per person decreases by 0.75 gallons. At the 95% confidence level the following variables were statistically significant: Total Annual Precipitation, % of CA residents who are White, % of Population w/ BA or Higher (25+), and Average Household Size. Ex: As the percentage of the population (25 and older) with Bachelor’s degrees or higher increases by 1%, daily domestic water usage per person decreases by 0.75 gallons. *The following variables were also included in the data, but were omitted from our regression because they were statistically insignificant: Agricultural Income, Land Area (sq. mi), Population Density (tot. pop/sq. mil), Median Household Income, and Private Nonfarm Employment.

Results: A multiple regression analysis was conducted to examine 7 potential predictors relationship with California residents’ daily water usage/person (gal.). A multiple regression analysis was conducted to examine 7 potential predictors relationship with California residents’ daily water usage/person (gal.). The multiple regression model with all 7 predictors produced an adjusted R 2 = (meaning 39.4% of the dependent variable, California’s residents daily water usage/person (gal.), is responding to the independent variables). The multiple regression model with all 7 predictors produced an adjusted R 2 = (meaning 39.4% of the dependent variable, California’s residents daily water usage/person (gal.), is responding to the independent variables). F(7, 58) = > F-crit.: indicates all coefficients of the independent variables are not statistically equal to zero. F(7, 58) = > F-crit.: indicates all coefficients of the independent variables are not statistically equal to zero. P = < 0.005: rejects the H 0 : stating that at the 95% confidence level, there is a significant relationship between the independent variable and California residents’ daily water usage/person (.gal) (4 out of 7 were statistically significant). P = < 0.005: rejects the H 0 : stating that at the 95% confidence level, there is a significant relationship between the independent variable and California residents’ daily water usage/person (.gal) (4 out of 7 were statistically significant). Looking at the p-values < 0.05 for each predictor we can state: Looking at the p-values < 0.05 for each predictor we can state: California residents’ daily water usage/person (gal.) has a moderately statistically significant direct association with percentage of Californians that are white AND average household size. California residents’ daily water usage/person (gal.) has a moderately statistically significant direct association with percentage of Californians that are white AND average household size. California residents’ daily water usage/person (gal.) has a moderately statistically significant inverse association with total precipitation AND percentage of CA population with a B.A. or higher (25+) California residents’ daily water usage/person (gal.) has a moderately statistically significant inverse association with total precipitation AND percentage of CA population with a B.A. or higher (25+) Possible improvements: Possible improvements: Expand sample size to every CA city. Expand sample size to every CA city. Examine data from multiple years. This study only considers data collected from Examine data from multiple years. This study only considers data collected from 2010.