Note that the formula for the circumference of a circle is πd, while the formula for the area of a circle is πr².
π≈3.14
A. C=πd
Simply plug in the numbers into the formula.
Diameter=Radius*2
17*2=34
C=34(π)
B. (π)(5²)
Plug in the numbers into the formula. Remember that half of the diameter is the radius.
C. (π)(4.5)
There are two possible formulas that could be used to calculate the circumference of a circle: πd and 2πr.
The expression above is simply multiplying the circle's radius times pi. Therefore, it is not a method that could be used to find the circumference of a circle.
D. (π)(6.5²)
Remember that the formula for calculating the area of a circle is πr².
Half of the diameter is 6.5 (13.5/2=6.5). 6.5 cm. is the radius. Now just plug the numbers into the formula.
(π)(6.5²)
Therefore, the last answer choice is the correct answer.
G = number of green = 7
S = number of striped = 8
T = number total = 10+7+8 = 25
probability of picking green = P(G) = G/T = 7/25
probability of picking striped = P(S) = S/T = 8/25
P(green and striped) = P(G)*P(S) ... events are independent
P(green and striped) = (7/25)*(8/25)
P(green and striped) = (7*8)/(25*25)
P(green and striped) = 56/625
P(green and striped) = 0.0896
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In summary, the answer as a fraction is 56/625
In decimal form, the answer is 0.0896
The value 0.0896 can be converted to percent form to get 8.96%
Answer:
First of all, he have to find out what 0.5% of the students is.
Second of all, find out what 0.5 of 100 is. 100 divided by 0.5 is 200.
Third of all, divide 200 from 639. This equals 3.195
Since it is asking about how many, I would go with about 3. After all, you can't have have half of a person, so the decimals shouldn't be added.
Step-by-step explanation:
Answer:
a) To determine the minimum sample size we need to use the formula shown in the picture 1.
E is the margin of error, which is the distance from the limits to the middle (the mean) of the confidence interval. This means that we have to divide the range of the interval by 2 to find this distance.
E = 0.5/2 = 0.25
Now we apply the formula
n = (1.645*0.80/0.25)^2 = 27.7 = 28
The minimum sample size would be 28.
b) To answer the question we are going to make a 90% confidence interval. The formula is:
(μ - E, μ + E)
μ is the mean which is 127. The formula for E is shown in the picture.
E = 0.80*1.645/√8 = 0.47
(126.5, 127.5)
This means that the true mean is going to be contained in this interval 90% of the time. This is why it doesn't seem possible that the population mean is exactly 128.