Answer:
Number 4 is correct.
Step-by-step explanation:
Answer:
30 each of 23% bars and 18 each of 79% bars
Step-by-step explanation:
If x is the number of 1 kg 23% copper bars, and y is the number of 1 kg 79% copper bars, then:
x + y = 48
0.23x + 0.79y = 0.44(48)
Substituting and solving:
0.23x + 0.79(48-x) = 0.44(48)
0.23x + 37.92 - 0.79x = 21.12
16.8 = 0.56x
x = 30
y = 48 - x
y = 18
You need 30 each of 23% bars and 18 each of 79% bars.
Answer:
y<7 since if you subtract 1 from both sides and then divide both sides by 5 you get y<7
M (Mean) = 20,500;
SD (Standard Deviation) = 55
1 ) 20,555 = 20,500 + 55 = M + 1 SD
Answer: 50% + 34.1% = 84.1%
2 ) 20.610 = 20,000 + 110 = M + 2 SD
Answer: 10% - ( 50% + 34.1% + 13.6% ) = 100% - 97.7% = 2.3%
3 ) 20,445 = 20,500 - 55 = M - 1 SD
Answer: 50% - 34.1% = 15.9%