Find s15 for the series -1 + -3 + -5 + -7 +
i am unsure of the formula to answer this equation. could someone give me a quick refresher. i do not want the answer, just the information necessary to find the answer myself. you!

Which of the following values cannot be probabilities? 0.08, 5 divided by 3, startroot 2 endroot, negative 0.59, 1, 0, 1.44, 3 divided by 5 select all the values that cannot be probabilities. a. five thirds b. 1.44 c. 1 d. startroot 2 endroot e. three fifths f. 0.08 g. 0 h. negative 0.59