Determine the percent of batteries with a lifetime between 38.4 hours and 44.4 hours, given that the battery’s mean lifetime is 42 hours with a standard deviation of 1.2 hours. Please show steps.

Mary used 1/7 of a spool of ribbon to complete 4 projects. she used the same amount of ribbon on each project. how much ribbon did she use on each project?

20 da is equal to a. 2,000 cm. b. 2 m. c. 20,000 cm. d. 20,000 mm

Currently, the largest cruise ship has a tonnage of 225,282 gross tons (gt). which of the following is a reasonable estimate for the tonnage of this cruise ship? a. 2 × 10^5 gt b. 2 × 10^6 gt c. 2 × 10^-5 gt d. 2 × 10^-6 gt