<h3>
Answer: 120</h3>
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Explanation:
S = sum of the first four values
S/4 = 70 since we divide the sum by 4 to get the mean of the first four values
S = 280 is the result after multiplying both sides by 4
Let x be the fifth unknown value. Adding it onto S leads to S+x = 280+x. This represents the sum of all five values.
Dividing that sum 280+x over 5 leads to the new mean 80, which leads to...
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(280+x)/5 = 80
280+x = 5*80
x+280 = 400
x = 400-280
x = 120
The fifth number is 120
Answer:
96
Step-by-step explanation:
Day 1: 144-8= 136
Day 2: 136-8= 128
Day 3: 128-8= 120
Day 4: 120-8= 112
Day 5: 112-8= 104
Day 6: 104-8=96
Answer:
This is a biased sample.
Step-by-step explanation:
This is because she gave a random sample, but the she had the convenience of the students being with her when she surveyed. So it'e not actually random. She could also worded the survey or gave a biased response.
Answer:
9pr = 2q^2
Step-by-step explanation:
28.
px^2 + qx + r = 0
If one root is A then the other root is 2A
We have A + 2A = -q/p and A*2A = r/p
So 3A = -q/p so A = -q/3p and A^2 = r/2p so A = √ (r / 2p)
Equating these 2 equations:-
-q/3p = √(r / 2p)
q^2 / 9p^2 = r / 2p
9p^2r = 2pq^2
9pr = 2q^2 (answer)
