Answer:
The mean of the combined math and verbal scores is 1100, while the standard deviation is 141.
Step-by-step explanation:
Normal variables
Normal variables have mean
and standard deviation 
When we add normal variables, the combined mean is the sum of both means, and the standard deviation is the square root of the sum of both variances. The distribution is still normal.
In this question:
Verbal:
.
Math: 
Combined:


The mean of the combined math and verbal scores is 1100, while the standard deviation is 141.
There are 4 terms in the expression
The dimensions of the smaller box are half those of the larger box. This means that:
*Length of smaller box= length of larger box/2= 24/2= 12cm.
*height of smaller box= height of larger box/2= 30/2= 15cm.
*width of smaller box= width of larger box/2= 10/2= 5cm.
#1) A
#2) E
#3) C
#4) 0.5840
#5) 0.6945
#6) 0.4911
#7) D
#8) G
#9) 0.4375
#10) 0.5203
The formula we use for this is

,
where

is the speed of sound, f is the frequency (or pitch) of the note, and λ is the wavelength.
#1) 0.77955f = 343
Divide both sides by 0.77955:
0.77955f/0.77955 = 343/0.77955
f = 439.997 ≈ 440. This is the pitch for A.
#2) 0.52028f = 343
Divide both sides by 0.52028, and we get f = 659.260. This is the pitch for E.
#3) 0.65552f = 343
Divide both sides by 0.65552, and we get f = 523.25. This is the pitch for C.
#4) 587.33λ = 343
Divide both sides by 587.33 and we get λ = 0.583999 ≈ 0.5840.
#5) 493.88λ = 343
Divide both sides by 493.88, and we get λ = 0.6945.
#6) 698.46λ = 343
Divide both sides by 698.46 and we get λ = 0.49108 ≈ 0.4911.
#7) 0.5840f = 343
Divide both sides by 0.5840 and we get f = 587.3288 ≈ 587.33. This is the pitch for D.
#8) 0.4375f = 343
Divide both sides by 0.4375 and we get f = 784. This is the pitch for G.
#9) 783.99λ = 343
Divide both sides by 783.99 and we get λ = 0.4375.
#10) 659.26λ = 343
Divide both sides by 659.26 and we get λ = 0.52028 ≈ 0.5203.
A= π r2
<span>r= 39.4/2=19.7
A= 19.7 x 19.7=388.09
A= pi x 388.09= </span>1218.6026<span>
A= 1218.6026
</span>