The life expectancy of a typical lightbulb is normally distributed with a mean of 4,000 hours and a standard deviation of 42 hours. what is the probability that a lightbulb will last between 3,875 and 4,055 hours?

a)0.8835
b)0.7825
c)0.9133
d)0.9035

33% of college students say they use credit cards because of the rewards program. you randomly select 10 college students and ask each to name the reason he or she uses credit cards. find the probability that the number of college students who say they use credit cards because of the rewards program is (a) exactly two, (b) more than two, and (c) between two and five inclusive. if convenient, use technology to find the probabilities.

During a bike challenge riders have to collect various colored ribbons each 1/2 mile they collect a red ribbon each eighth mile they collect a green ribbon and each quarter mile they collect a blue ribbion wich colors of ribion will be collected at the 3/4 markrer

Which of the following three dimensional figures has a circle as it’s base