Answer:
7.1
Step-by-step explanation:
Here's how we have to set this up. We will start with the first statement, which algebraically looks like this:
x + 6.5 = y (since we don't know what x is, we don't know what the sum of x and 6.5 is. We will call that new number y.)
Next, we are dividing that sum, y, by 13.6:
(again, since we don't know what y is, we don't know what y divided by 13.6 is. We will call that new number z.)
Finally, the quotient, z, is multiplied by 5:
5z
Now we work backwards, subbing in our unknowns, one at a time.
5z
If z = , we sub it into the expression 5z:
and
if y = x + 6.5 we plug that in for y:
since we know that whole mess is equal to 5. NOw we solve for x, the original number. Begin by dividing both sides by 5 to get:
Now multiply both sides by 13.6 to get:
x + 6.5 = 13.6 so
x = 7.1
Check this if you'd like by plugging in the 7.1 for x in the intial equation to solve for y, then plug that into the next equation to solve for z, then see if they're equal (they are, but test it out for yourself).
Answer:
Option A
Step-by-step explanation:
System of the inequalities is,
y ≥ 2x
y < x + 4
By satisfying these inequalities with the points given in the options we can get the answer.
Option (A). (2, 5)
y ≥ 2x
5 ≥ 2(2)
5 ≥ 4
True.
y < x + 4
5 < 2 + 4
5 < 6
True
Therefore, Option (1) is the answer.
Option (B) (1, 6)
y ≥ 2x
6 ≥ 2(1)
6 ≥ 2
True.
y < x + 4
6 < 1 + 4
6 < 5
False.
Therefore, it's not the solution.
Option (C) (2, 3)
y ≥ 2x
3 ≥ 2(2)
3 ≥ 4
False.
y < x + 4
4 < 2 + 4
4 < 6
True.
Therefore, It's not the solution.
Option (D) (1, 5)
y ≥ 2x
5 ≥ 2(1)
5 ≥ 4
True.
y < x + 4
5 < 1 + 4
5 < 5
False.
Therefore, It's not the solution.
Answer:
D. The 95% confidence interval ranges from 42.78 to 47.22 hours.
Step-by-step explanation:
In a sample of 50 households, the mean number of hours spent on social networking sites during the month of January was 45 hours. In a much larger study, the standard deviation was determined to be 8 hours.
Here,
n = sample size = 50,
μ = mean = 45,
σ = standard deviation = 8,
We know that, confidence interval will be,
For a confidence interval of 95%, we use z = 1.96, putting the values