Step-by-step explanation:
If segment AD contains point B and, then A, B, C and D lies on the same straight line as shown in the attachment.
To show that point C is the middle of point BD, we musr show that segment BC is equal to CD i.e BC = CD.
From the diagram, AC = AB+BC
Given AC = 12cm and AB = 4cm
BC = AC-AB
BC = 12cm - 4cm
BC = 8cm
Also AD = AB+BC+CD
Given AD = 20cm, AB = 4cm and BC = 8cm
CD = AD-(AB+BC)
CD = 20-(4+8)
CD = 20-12
CD = 8cm
It can be seen that BC = CD = 8cm, hence C is the midpoint of B and C.
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.
