The average life of a lightbulb is 2500 h, with a standard deviation of 200 h. suppose that 10,000 bulbs are purchased to equip a new building. assume that the lives are normally distributed. how many of the light bulbs would be expected to burn out after just 1800 h?

Me its important ! marge runs an ice cream parlor. her speciality is triple chocolate sundaes. she can prepare 1 sundae every 2 minutes, and she earns $1.20 for each sundae she makes . if she just makes sundaes for a single shift of at most 4 hours and at least 2 hours , which function relates her earnings to the number of minutes she works?