Answer:
i thinkbit is C but im in 6th grade and at may 5 i. not there yet
4y + 228 = 352
4y = 352 - 228
4y = 124
--- ----
4 4
------------
| y = 31 |
------------
hope this helps
Answer:
Step-by-step explanation:
We want to determine a 95% confidence interval for the population mean.
Number of sample, n = 56
Mean, u = 645 hours
Standard deviation, s = 31 hours
For a confidence level of 95%, the corresponding z value is 1.96.
We will apply the formula
Confidence interval
= mean ± z ×standard deviation/√n
It becomes
645 ± 1.96 × 31/√56
= 645 ± 1.96 × 4.142
= 645 ± 8.12
The lower end of the confidence interval is 645 - 8.12 =636.88
The upper end of the confidence interval is 645 + 8.12 =653.12
Therefore, with 95% confidence interval for the population mean life of fluorescent light bulbs is between 636.88 hours and 653.12 hours
Answer:
40/13 hours
Step-by-step explanation:
Let 1 represent the room being painted.
1/5 would represent 1/5 of a room painted in 1 hour.
1/8 would represent 1/8 of a room being painted in 1 hour
But they are are working together so
(1/5)x + (1/8)x = 1
The lowest common denominator is 5 * 8 = 40
[(1/5)x * 40 + (1/8)x * 40] = 1
8x + 5x = 40
13x = 40
x = 40/13
x = 3.077 hours
But you want a fraction as your answer so it is 3 1/13 or 40/13
You should notice that 3.077 is smaller than the lowest amount of time both of them use. That always happens with these questions.
Answer:
The area is 196π, or 615.752160 when evaluated to 6 decimal places.
Step-by-step explanation:
There is an equation for the area of a circle:
A=π
, Where A is the area and r is the radius. π is π, it is its own number. Plugging in the radius stated we can evaluate:
A=π(
)
A=196π
If we write out π and evaluate with an (un)reasonable amount of decimal places:
π≅3.1415926536
A=196×(3.1415926536)
A≅615.752160
