Answer:
The data item is 
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Mean of 400 and a standard deviation of 60.
This means that 
z=3
We have to find X when Z = 3. So




The data item is 
Answer:
I Know the answer because I am in k12 too.
The answer is 37.5%
Step-by-step explanation:
$80 - $50 = $30
$30 * 100 / $ 80 = 37.5%
answer: 37.5% of decrease.
To calculate the average, we will use the following rule:
average = sum of scores / number of scores
sum of scores = 85+72+89+90 = 336
number of scores = 4
average = 336/4 = 84%
9x^2 + 24x + 16
= (3x + 4)(3x + 4)
length of each side = 3x + 4 units
B
16x^2 - 25y^2
= (4x - 5y)(4x + 5y)
Dimensions are (4x - 5y) by (4x + 5y) units.
Answer:
0.21186
Step-by-step explanation:
We solve the above question using the z score formula.
z = (x-μ)/σ, where
x is the raw score = 3100g
μ is the population mean = 3500g
σ is the population standard deviation = 500g
z = 3100 - 3500/500
z = -0.8
Probability value from Z-Table:
P(x<3100) = 0.21186
The probability that a baby is born that weighs less than 3100g is 0.21186