1. a type of battery-operated led lights has a known mean lifetime 7.8 hrs with standard deviation 0.2. assuming that the lifetimes of these led lights have a nearly symmetric/bell-curve distribution, find the percent (%) of these led lights having lifetime between 7.6 and 7.8 hours.

What is the prime factorization of 195

Which sentence describes why polygon mnop is congruent to polygon jklp? a. polygon jklp maps to polygon mnop through a translation. b. polygon jklp maps to polygon mnop through a rotation. c. polygon jklp maps to polygon mnop through a dilation. d. polygon jklp maps to polygon mnop through a stretch.

Solve the given system of equations. 2y= -x+9 , 3x-6= -15