SOLUTION: Please can someone help me I have been trying for hours! A college entrance exam has a mean of 1400 and standard deviation of 200. A college will only accept the top 2.5% or hig

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Question 933215: Please can someone help me I have been trying for hours!
A college entrance exam has a mean of 1400 and standard deviation of 200. A college will only accept the top 2.5% or higher. What is the lowest score they need on the exam?
Can someone please help and show the formula! I would appreciate it so much!
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
mean of 1400 and a standard deviation of 200. z+=+blue%28x+-+1400%29%2Fblue%28200%29
A college will only take applicants in the top 2.5% or higher.
What is the lowest score they would need on the entrance exam
200z + 1400 = x
z = invNorm(.975).
invNorm(.975) = 1.96 can be found from a table or Using calculator 0r Excel Function
.....
200(invNorm(.975) + 1400 = 200(1.96) + 1400 = 1792, lowest score
.....
Note: 1 - .025 = .975 (z-value found...97.5% of the Area Under NOrmal curve to the left of that value.
......
For the normal distribution: Below: z = 0, z = ± 1, z= ±2 , z= ±3 are plotted.
97.5% of the Area under the standard normal curve is to the left of z = 1.96
Note: z = 0 (x value: the mean) 50% of the area under the curve is to the left and 50% to the right

stattrek.com a great reference for statistics