Answer:
Nina practiced the viola for 11.25 hours last week.
Step-by-step explanation:
Juan practiced the violin for 9 hours last week. For each 3 hours that he practices the violin, he practices 2.5 hours of cello. So
3h violin - 2.5h cello
9h violin - xh cello


He practiced 7.5 hours of cello, the same as Nina.
For every 3 hours Nina spends practicing the viola she practices the cello for 2 hours. So:
3h viola - 2h cello
xh viola - 7.5h cello



Nina practiced the viola for 11.25 hours last week.
"at least " means her score has to be more or equal 94
94≤(85+91+x)/3
it looks like correct answer is e.
Answer:
Maximize C =


and x ≥ 0, y ≥ 0
Plot the lines on graph




So, boundary points of feasible region are (0,1.7) , (2.125,0) and (0,0)
Substitute the points in Maximize C
At (0,1.7)
Maximize C =
Maximize C =
At (2.125,0)
Maximize C =
Maximize C =
At (0,0)
Maximize C =
Maximize C =
So, Maximum value is attained at (2.125,0)
So, the optimal value of x is 2.125
The optimal value of y is 0
The maximum value of the objective function is 19.125
Given side length "a" and angle "A", calculate the diagonals<span><span>
p = square root [( 2a^2 - 2a^2 cos(A) )]
</span>q = </span><span>square root [( 2a^2+ 2a^2 cos(A) )]</span>
http://www.calculatorsoup.com/calculators/geometry-plane/rhombus.php
side = 36
cos (32) = 0.84805
p = <span>small diagonal = </span>
<span>
<span>
<span>
19.8457652914
</span>
</span>
</span>
<span><span>
</span>
</span>
q =
large diagonal =
<span>
<span>
<span>
69.2108777578
</span>
</span>
</span>
We are looking to find P(X>60 students)
X is normally distributed with mean 50 and standard deviation 5
We need to find the z-score of 60 students

To find the probability of P(Z>2), we can do 1 - P(Z<2)
So we read the probability when Z<2 which is 0.9772, then subtract from one we get 0.0228
The number of students that has score more than 60 is 0.0228 x 1000 = 228 students