The linear correlation between violent crime rate and percentage of the population that has a cell phone is minus0.918 for years since 1995. do you believe that increasing the percentage of the population that has a cell phone will decrease the violent crime rate? what might be a lurking variable between percentage of the population with a cell phone and violent crime rate?

Apsychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. she randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. does this sampling plan result in a simple random sample? why or why not? no, because each group of 200 students in the sample does not have the same chance of being selected. yes, because each group of 200 students in the sample has the same chance of being selected. no, because each individual student does not have an equal chance of being selected. yes, because each individual student has the same chance of being selected.

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?

Acentral angle measuring 160 degrees intercepts an arc in a circle whose radius is 4. what is the length of the arc the circle formed by this central angle? round the length of the arc to the nearest hundredth of a unit. a) 4.19 units b) 6.28 units c) 12.57 units d) 12.57 square units