Answer:
<h3>73220±566.72</h3>
Step-by-step explanation:
The formula for calculating the confidence interval is expressed as;
CI = xbar ± z*s/√n
xbar is the sample mean = $73,220
z is the z score at 99% CI = 2.576
s is the standard deviation = $4400
n is the sample size = 400
Substitute the given values into the formula;
CI = 73,220 ± 2.576*4400/√400
CI = 73,220 ± 2.576*4400/20
CI = 73,220± (2.576*220)
CI = 73220±566.72
Hence a 99% confidence interval for μ is 73220±566.72
Let's begin by listing out the information given to us:
We start out by observing that Triangles MKR & ACD are similar or proportional

We will solve for the missing side by using the similar triangle theorem. This is shown below:~
Answer:
(x−3)(x−5)
Step-by-step explanation:
Hope this helped
Answer:
b)0, yes
Step-by-step explanation:
Given:
Vectors (4,8) . (6,-3)
Finding inner product of vectors:
= 4x6 + 8x-3
=24-24
=0
Now to check the angle between them using formula a.b=|a|.|b|cosθ
|a|= 
=8.9
|b|=
=6.7
Putting values of a.b=0 and |a|=8.9, |b|=6.7 in a.b=|a|.|b|cosθ we get,
0= 8.9(6.7)cosθ
cosθ =0
θ=90 degrees
Hence the two vectors are perpendicular !