Answer:
x = 4
Step-by-step explanation:
2 + 3(3x - 6) = 5(x - 3) + 15
Expand the parenthesis:
2 + 9x - 18 = 5x - 15 + 15
Simplify:
9x - 16 = 5x
Subtract 5x from both sides:
4x - 16 = 0
Add 16 to both sides:
4x = 16
Divide both sides by 4:
x = 4
Answer:
- 35 grams of 11.43% solution
Step-by-step explanation:
The end solution has same volume as initial volumes of mixture.
The concentration of solution is calculated as below
- 10*0.15 + 25*0.1 = 4 g
- 4 / 35*100% = 11.43% (rounded)
The 68-95-99.7 rule tells us 68% of the probability is between -1 standard deviation and +1 standard deviation from the mean. So we expect 75% corresponds to slightly more than 1 standard deviation.
Usually the unit normal tables don't report the area between -σ and σ but instead a cumulative probability, the area between -∞ and σ. 75% corresponds to 37.5% in each half so a cumulative probability of 50%+37.5%=87.5%. We look that up in the normal table and get σ=1.15.
So we expect 75% of normally distributed data to fall within μ-1.15σ and μ+1.15σ
That's 288.6 - 1.15(21.2) to 288.6 + 1.15(21.2)
Answer: 264.22 to 312.98
3\4
because the spaces are bigger draw a model and you will see
Mean = total score : frequency
mean x frequency = total score
so
83 = total score : 6
83 × 6 = total score
498 = total score
so the sum of the 6 test scores is 498
