A variable is a quantity that can change; the word also refers to the letter or symbol that represents this quantity. In a proportional relationship, one variable is the independent variable, and one is the dependent variable. They are often called "x" and "y," but any letters can be used. The value of the dependent variable depends on the value of the independent variable. In the relationship between number of scoops of ice cream and total price, we can call number of scoops "x" and total price "y." Y is dependent because its value depends on x, the number of scoops you purchase. Ursula makes $5 for every 1 dog she walks. In the relationship between dollars earned and dogs walked, is the dependent variable, which is often called .

Acell phone company offers two plans to its subscribers. at the time new subscribers sign up, they are asked to provide some demographic information. the mean yearly income for a sample of 40 subscribers to plan a is $45,000 with a standard deviation of $9,200. for a sample of 25 subscribers to plan b, the mean income is $64,300 with a standard deviation of $7,100. at the 0.025 significance level, is it reasonable to conclude the mean income of those selecting plan b is larger? assume unequal population standard deviations. hint: for the calculations, assume the plan a as the first sample. what is the decision rule? (negative amount should be indicated by a minus sign. round your answer to 3 decimal places.) compute the value of the test statistic. (negative amount should be indicated by a minus sign. round your answer to 2 decimal places.) what is your decision regarding h0 ? reject h0 fail to reject h0 compute the p-value. less than 0.01 between 0.01 and 0.025 between 0.025 and 0.05 between 0.05 and 0.10 greater than 0.10