Part a: For variable X using z score you have (x-30)/10, replace X for this expression in (a), i mean Z=2+10((x-30)/10) = 2+x-30= put this in the way of z score = (x-18)/1, so the mean is 18 and standard deviation is 1.
Part b: Z=X+Y= (x-30)/10 + (x-20)/8 = solve adding fractions = (18x-440)/80 now divide all the numbers between 18 (because you need to show as z score way) = (x-24.4)/4.4, so the mean is 24.4 and standard deviation is 4.4.
For part c,do the same.
Answer:
The answer to number 1 is A.
Step-by-step explanation:
To find this answer, I made 1 1/3 into one big fraction. I multiplied the denominator by the whole number (3x1) and then added that product to the numerator. (3+1). The new fraction is now 4/3 (you keep the denominator the same). The next step is to multiply 4/3 by 3/8. When multiplying fractions, you multiply straight across (the numerator by the numerator, and the denominator by the denominator). Your answer is now 12/24. The final step is to simplify the answer. Since 12 is half of 24, the answer is 1/2.
10,50 - 6,00 = 4,50
6............100%
4,50..........x
6x = 450
x = 450/6
x = 75%
Based on the given variation, y does not vary directly with x and the constant of variation are 8, 3.2 and 1.25 respectively.
<h3>Variation</h3>
y = k × x
where,
k = constant of proportionality
y = -40
x = -5
y = k × x
-40 = k × -5
-40 = -5k
k = -40/-5
k = 8
when,
y = 8 and x = 2.5
y = k × x
8 = k × 2.5
8 = 2.5k
k = 8/2.5
k = 3.2
when,
y = 5 and x = 4
y = k × x
5 = k × 4
5 = 4k
k = 5/4
k = 1.25
Learn more about variation:
brainly.com/question/6499629
#SPJ1
