Answer:
is it multiple choice answers ?
Answer:
a) 20.16; b) 20.49 and 21.51
Step-by-step explanation:
We use z scores for each of these. The formula for a z score is
.
For part a, we want the 20th percentile; this means we want 20% of the data to be lower than this. We find the value in the cells of the z table that are the closest to 0.20 as we can get; this is 0.2005, which corresponds with a z score of -0.84.
Using this, 21 as the mean and 1 as the standard deviation,
-0.84 = (X-21)/1
-0.84 = X-21
Add 21 to each side:
-0.84+21 = X-21+21
20.16 = X
For part b, we want the middle 39%. This means we want 39/2 = 19.5% above the mean and 19.5% below the mean; this means we want
50-19.5 = 30.5% = 0.305 and
50+19.5 = 69.5% = 0.695.
Looking these values up in the cells of the z table, we find those exact values; 0.305 corresponds with z = -0.51 and 0.695 corresponds with z = 0.51:
-0.51 = (X-21)/1
-0.51 = X-21
Add 21 to each side:
-0.51+21 = X-21+21
20.49 = X
0.51 = (X-21)/1
0.51 = X-21
Add 21 to each side:
0.51+21 = X-21+21
21.51 = X
<span>Length = l</span>
<span>
Width = w</span>
<span>
Perimeter = p = 100
</span>
<span>Perimeter of rectangle = 2(l+w)</span>
<span>
100 = 2 (4w + w)</span>
<span>
100 = 2(5w)</span>
<span>
100 = 10w</span>
<span>
100/10 = w</span>
<span>
10 = w</span>
<span>
w = 10
Area of rectangle = length * width</span>
<span>
a = l*w</span>
<span>
a = 4w*w</span>
<span>
a = 4w^2............(1)</span>
<span>
Put the value of w in (1)</span>
<span>
a = 4(10)^2</span>
<span>
a= 4(100)</span>
<span>
a = 400 yd^2</span>
Answer:
leading coefficient is 18
and the degree is also 18
Step-by-step explanation: