Iwill fan and ! a gray-scale digital camera with 1,000,000 pixels takes a picture (the picture is made of 1,000,000 parts and each part has a certain amount of gray). a histogram is made where the data is the amount of gray in each of these parts. the histogram looks bell-shaped with a mean of 125 gray levels and a standard deviation of 15. how many pixels are brighter than 163 gray levels? 5000 10,000 160,000 50,000

5000  
First, let's determine how many standard deviations from the mean the value
(163+1) = 164 is:
 (164 - 125)/15 = 39/15 = 2.6 
 Now using a standard normal table, look up 2.6 to determine the percentage of points that would be that far from the mean. I find a value of 0.49534. Note that is is a half value. So the percentage that will be higher than that will be 0.5 - 0.49534= 0.00466 
 Now multiply by the number of points overall, getting
 0.00466 * 1000000 = 4660 
 So there will be approximately 5000 pixels brighter than 163 gray levels.