Answer:
532
Step-by-step explanation:
The score that represents the top 20% = A score = 80%
Z score for 80% percentile = 0.842
We solve using the z score formula
z = (x-μ)/σ, where
x is the raw score = ??
μ is the population mean = 490
and σ is the population standard deviation = 50
Hence:
0.842 = x - 490/50
Cross Multiply
0.842 × 50 = x - 490
x = 0.842 × 50 + 490
x = 42.1 + 490
x = 532.1
Approximately = 532
Therefore, the test score = 532
The mean is (x+μ)/<span>σ</span> as determined by the Canaon-Heinlich equation.
Answer:
b=5
Step-by-step explanation:
the answer is in the image above
43x5= 215
215 pupils
215-200=15
15 seats
A. 10 boys to 12 girls because both numbers in the given ratio have been multiplied by two 5*2=10 6*2=12. None of the other options can be simplified to the original given ratio of 5:6.
