Answer:
3.4
Step-by-step explanation:
Standard deviation of a population is defined as:
σ² = ∑(xᵢ − μ)² / n
The standard deviation of a sample is defined as:
s² = ∑(xᵢ − x)² / (n - 1)
It's not clear which one we have, so let's calculate both.
First, we must find the mean.
μ = (5+12+15+10+12+6+8+8) / 8
μ = 9.5
Now we find the squares of the differences:
(5-9.5)² + (12-9.5)² + (15-9.5)² + (10-9.5)² + (12-9.5)² + (6-9.5)² + (8-9.5)² + (8-9.5)²
= 80
Divide by n:
σ² = 80 / 8
σ² = 10
And take the square root:
σ = √10
σ ≈ 3.2
That's not one of the answers, so let's try the standard deviation of a sample instead of a population.
Instead of dividing by n, we'll divide by n-1:
s² = 80 / 7
And take the square root:
s = √(80/7)
s ≈ 3.4
So that must be it.
Answer:
x + y = 60 and 1.55x + 1.4y = 88.20 and the solution is x = 32 and y = 28.
Mr. Sanchez’s class earned more money by $10.4.
Step-by-step explanation:
Mr. Sanchez’s class sold fruit pies for $1.55 each and Mr. Kelly’s class sold bottles of fruit juice for $1.40 each.
Let the number of sold fruit pies is x and bottles of fruit juice is y.
So, from the given condition we can write
x + y = 60 ........ (1)
⇒ 1.4x + 1.4y = 84 ....... (2) and
1.55x + 1.4y = 88.20 ........ (3)
Now, solving equations (2) and (3) we get (1.55 - 1.4)y = (88.2 - 84)
⇒ y = 28
And from equation (1) we get x = 60 - 28 = 32.
Therefore, Mr. Sanchez’s class earned more money. (Answer)
Now, this class have earned $(32 × 1.55 - 28 × 1.4) = $10.4 more. (Answer)
Answer:
1) THE TOTAL NUMBER OF MARKS TELLS YOU THE SIZE OF THE DATA SET.
2)hISTOGRAM
:)
Step-by-step explanation:
With any parallelogram, the diagonals bisect each other. This is another way of saying that they cut each other in half.
FH is one diagonal that is split into two equal pieces by the other diagonal EG.
The two parts of FH (KH and KF) are congruent to each other, so KH = KF. They combine back to FH
By the segment addition postulate
KH + KF = FH
KH + KH = FH .... KF has been replaced with KH (works because KF = KH)
2*KH = FH
Now use substitution
2*KH = FH
2*15 = FH .... replace KH with 15 (since KH = 15)
2*15 = 4x-2 ... replace FH with 4x-2 (since FH = 4x-2)
and solve for x
2*15 = 4x-2
30 = 4x-2
30+2 = 4x-2+2 ... add 2 to both sides
32 = 4x
4x = 32
4x/4 = 32/4 ... divide both sides by 4
x = 8
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Answer: x = 8
