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:
angle y
58 + 38 + y = 180 (angle sum property)
96 + y = 180
y = 180 - 96
y = 84
angle x
x = 29 (58/2)
(angle subtended by an arc at centre is double the arc at any point on remaining part of centre)
the values of x = 29 and y = 84
500 (the current collection) + 10 (the weekly addition) x 20 (weeks to add)
500 + 10*20 (Multiplication comes before addition)
500+200
700
Answer:


Step-by-step explanation:
The velocity vector is the integral of the acceleration vector i.e.



When
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The position vector is the integral of the velocity vector i.e.



When
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. Inserting these values in
,


