Answer:
<h2>x = 114</h2>
Step-by-step explanation:
0.2x – 1.8/5 = 4.2
0.2x - 1.8 = 4.2 (5)
x =<u> 21 + 1.8 </u>
0.2
x = 22.8 / 0.2
x = 114
Answer:
Numbers of students at a primary school before= 240
Number of increased students =42
Again,
Increased number of students in percent(%)= 42/240×100%= 17.5%
Therefore 17.5% students are increased this year.
Answer:
Probably unequal ( B )
Step-by-step explanation:
<u>experimental group = 10</u>
using 85% ethanol gasoline
mean = 240 pounds per 100 miles
standard deviation = 20 pounds
<u>control group = 14 vehicles </u>
using regular gasoline
mean = 252 pounds per 100 miles
standard deviation = 15 pounds
comparing the sample variance of each group shows that they are probably unequal using the equation below
Variance for a sample set of data = ∑ ( x - X ) ^2 / n - 1
where n = number of events
X = mean value
x = value of events
It increased by 7.7 degreese because it goes from -16.5 to -8.8. You would have to subtract 8.8 from 16.5 but it is easier to make them positive.