The amount of time a certain brand of light bulb lasts is normally distribued with a
mean of 1600 hours and a standard deviation of 55 hours. using the empirical rule,
what percentage of light bulbs last between 1490 hours and 1710 hours?

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.

Anyone know these questions? i need ,.

In an isosceles triangle, the vertex angle is 112 degrees. what is the measure of each base. a.34 b.24 c.44 d.54