Z-31=16??? I just got into the Z section in algebra and my teacher gave us a paper with no explanation plz help ty!
1 answer:
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Answer:
a) 0.6915; b) 2.83 years
Step-by-step explanation:
For part a,
The formula for a z score is
Our mean, μ, is 3.25 and our standard deviation, σ, is 0.5.
This gives us
z = (3-3.25)/0.5 = -0.25/0.5 = -0.5
Using a z table, we see that the area under the curve to the left of this is 0.3085. However we want the area to the right; this means we subtract from 1:
1-0.3085 = 0.6915
For part b,
We look in the cells of a z table to find the value closest to 20%, or 0.2000. This is 0.2005, which corresponds with a z score of -0.84:
-0.84 = (X-3.25)/0.5
Multiply both sides by 0.5:
0.5(-0.84) = ((X-3.25)/0.5)(0.5)
-0.42 = X-3.25
Add 3.25 to each side:
-0.42+3.25 = X-3.25+3.25
X = 2.83
The advertised life would be 2.83 years.
Answer:
B
Step-by-step explanation:
- First find the perdendicular slope (flip and change sign) : m= -
- Then set up your equation using the given ordered paired to find your y-intersept: -1 = -
(5) + b
- Caluclate the product: -1 = -
+ b
- Move the variable to the left-hand side and change its sign : -b - 1 = -
- Calculate the sum: -b = -
- Change the sign : b=
- Use the slope and y-intersept to creat the equation: y = -