Answer:
a) 90.1
b) $35.6
c) 3.0915 hours
Step-by-step explanation:
The z-score measures how many standard deviations a score X is above or below the mean.
It is given by the following formula:
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
In which
is the mean and
is the standard deviaition.
In all three cases, we have to find X
a. Final exam scores: Allison’s z-score = 2.30, μ = 74, σ = 7.
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
![2.30 = \frac{X - 74}{7}](https://tex.z-dn.net/?f=2.30%20%3D%20%5Cfrac%7BX%20-%2074%7D%7B7%7D)
![X - 74 = 7*2.3](https://tex.z-dn.net/?f=X%20-%2074%20%3D%207%2A2.3)
![X = 90.1](https://tex.z-dn.net/?f=X%20%3D%2090.1)
b. Weekly grocery bill: James’ z-score = –1.45, μ = $53, σ = $12.
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
![-1.45 = \frac{X - 53}{12}](https://tex.z-dn.net/?f=-1.45%20%3D%20%5Cfrac%7BX%20-%2053%7D%7B12%7D)
![X - 53 = -1.45*12](https://tex.z-dn.net/?f=X%20-%2053%20%3D%20-1.45%2A12)
![X = 35.6](https://tex.z-dn.net/?f=X%20%3D%2035.6)
Mean and standard deviation in dollars, so the answer also in dollars.
c. Daily video game play time: Eric’s z-score = –0.79, μ = 4.00 hours, σ = 1.15 hours.
![Z = \frac{X - \mu}{\sigma}](https://tex.z-dn.net/?f=Z%20%3D%20%5Cfrac%7BX%20-%20%5Cmu%7D%7B%5Csigma%7D)
![-0.79 = \frac{X - 4}{1.15}](https://tex.z-dn.net/?f=-0.79%20%3D%20%5Cfrac%7BX%20-%204%7D%7B1.15%7D)
![X - 4 = -0.79*1.15](https://tex.z-dn.net/?f=X%20-%204%20%3D%20-0.79%2A1.15)
![X = 3.0915](https://tex.z-dn.net/?f=X%20%3D%203.0915)
Mean and standard deviation in hours, answer in hours.
Answer:
A
Step-by-step explanation:
Distribute the (-)
6x^3y^3+x^3y^3 + 5x^2y^2 - x^2y^2 - x^2y+x^2y +xy^2 +3x+3x +2-4
Cancel out bold and add:
7x^3y^3 + 4x^2y^2 +xy^2+6x-2
Answer:
in which class r u?............
Answer:
Its a rational number
Step-by-step explanation:
because a rational number has fractions and -22 is a fraction or a decimal