Times for an ambulance to respond to a medical emergency in a certain town are normally distributed with a mean of 400 seconds and a standard deviation of 50 seconds.Suppose there are 144 emergencies in that town.In about how many emergencies are the response times expected between 350 seconds and 450 seconds?49519698

Answer:Step-by-step explanation:In the normal distribution curve, the mean is in the middle and each line to the left and to the right of that mean represent 1- and 1+ the standard deviation.  If our mean is 400, then 400 + 50 = 450; 450 + 50 = 500; 500 + 50 = 550.  Going from the mean to the left, we subtract the standard deviation and 400 - 50 = 350; 350 - 50 = 300; 300 - 50 = 250.  We are interested in the range that falls between 350 and 450 as a percentage.  That range represents the two middle sections, each containing 34% of the data.  So the total percentage of response times is 68%.  We are looking then for 68% of the 144 emergency response times in town.  .68(144) = 97.92 or 98 emergencies that have response times of between 350 and 450 seconds.