student cell phone users are selected to try each battery in their usual mix of “talk” and “standby”
and to record the number of hours until recharge was needed.
(a) Do these results show that the new battery has significantly longer life at α = .05? State your hypotheses and show all steps clearly.
(b) Is the decision close?
(c) What is the mean and standard error?
Recently Asked Questions
- Choose the correct words: When a chemical system is at dynamic equilibrium, there (are/ are not) visible changes in the system. In a saturated solution,
- Choose the correct word that fits. In a saturated solution, the rate of crystallizing is (equal to/ greater than/ less than) the rate of dissolving. In a
- A distribution of test scores has a mean of 72 and a standard deviation of 4. Sharon's test score is 9 points above the mean. Jill has a z-score of +1.20.