Answer:
The answer is below
Step-by-step explanation:
The z score is a score used to determine the number of standard deviations by which the raw score is above or below the mean, it is given by the equation:

Given that μ = 650, σ = 50. To find the probability that 5 students who have a mean of 490, we use:

From the normal distribution table, P(x < 490) = P(Z < -7.16) = 0.0001 = 0.01%
Since only a small percentage of people score about 490, hence the local newspaper editor should write a scathing editorial about favoritism
Answer:
$10,880
Step-by-step explanation:
15% = 15 ÷ 100 = 0.15
So 15% of 12800 = 0.15 x 12800 = 1920
Therefore, 12800 - 1920 = 10880
OR
12800 x (1 - 0.15) = 10880
6( x - 4) = 7
6 x - 24 = 7
6 x = 7 + 24
6 x = 31
x = 31/6
6 ( 31/6 - 4) = 7
186/6 - 24 = 7
186/6 = 144/6 = 7
42/6 = 7
7 = 7