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:
a. $270
b. $3,278.18
Step-by-step explanation:
Given that
The principal amount is $3,000
Annual rate of interest is 3%
And, the time period is 3 years
We need to find out the simple interest & compound interest
The following formulas should be used
a. For simple interest
= Principal × rate of interest × time period
= $3,000 × 3% × 3 years
= $270
b. For compound interest
= Principal × (1 + rate of interest)^time period
= $3,000 × (1 + 0.03)3
= $3,000 × 1.03^3
= $3,278.18
Volume = <span>πd^2h/4
245 = </span><span>π x d^2 x 5/4
d^2 = (245 x 4)/5</span><span>π = 62.39
d = sqrt(62.39) = 7.9 units
</span>
Answer:
<h3>-4≤y≤7</h3>
Step-by-step explanation:
Given the inequality expressions
4y - 7 ≤ 3y and 3y≤5y+8
For 4y - 7 ≤ 3y
Collect like terms
4y - 3y ≤ 7
y ≤ 7
For 3y≤5y+8
Collect like terms
3y - 5y ≤ 8
-2y ≤ 8
y ≥ 8/-2
y ≥ -4
Combining both solutions
-4≤y≤7
<em>Hence the range of values of y that satisfies both inequalities is -4≤y≤7</em>
