Answer:

Step-by-step explanation:
<u><em>the mean in period</em></u> 1 :
(2.3+2.1+2.2+2.2+2.2+2.1+2.4+2.5+2.2+2.0+1.9+1.9+2.1+2.2+2.3)÷15=21.733...
<u><em>the mean in period</em></u> 2 :
(2.3+2.1+3.3+1.5+3.6+1.6+3.0+1.1+4.7+2.1+2.4+1.9+2.8+0.5+2.3)÷15=23.466...
Since 23.466 > 21.733 then “The mean in period 2 is higher than the mean in period 1”.
Answer:
nikes
Step-by-step explanation:
Answer:
179, 180, 181
Step-by-step explanation:
a +a +1 +a +2 =540
3a +3 =540
3a =540 - 3
3a=537
a=537 :3
a=179 (the first number
b=179 +1 =180 (the second number
c=179 +2 =181 (the third number
540ml with 12% solution
get 12% of 540
540 times 0.12 = 64.8 ml of pure acid