Plz do this question if you did I will very appreciated you. plz.
1 answer:
The area formula of a circle is × π.
With that being said, we can solve both problems!
Starting with part A:
-The radius we know is 21cm. From there, we can substitute in our formula with the new value.
x π
From there, we can square our radius:
(21 x 21) x π
(441) x π
And finally, we can multiply by pi to get our answer.
(441) x π
1385.44236023
Which rounded to the nearest tenth is 1385.4. Therefore, the area of the porthole is 1385.4 centimetres.
The second part can be followed with the same process, hopefully you understand the concept enough to where you're comfortable solving problems like this on your own. Feel free to reach out if you have any further trouble!
<em>Hope this helped! :)</em>
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Answer:
statistic value t= 5.43
p-value: < 0.00001.
Step-by-step explanation:
Hello!
To obtain information over the corrosion-resistance properties of a certain type of steel conduit a random sample of 45 specimens was taken and buried for two years.
The study variable is:
X: Max. penetration of a steel conduit.
The data of the sample
n= 45
sample mean X[bar]= 53.4
sample standard deviation S= 4.2
The conduits are manufactured to have a true average penetration of at most 50 mills, symbolically: μ ≤ 50
The hypothesis is:
H₀: μ ≤ 50
H₁: μ > 50
α: 0.05
To choose the corresponding statistic to use to study the population mean, the variable must have a normal distribution. There is no available information to check this, so I'll just assume that the variable has a normal distribution and, since the population variance is unknown and the sample is small, the statistic to use is a Student t.
Under the null hypothesis, the critical region and the p-value are one-tailed.
Critical value:
Rejection rule:
Reject the null hypothesis when t ≥ 1.68
t=
t= 5.43
The calculated value is greater than the critical value, thedecision is to rject the null hypothesis.
p-value:
P(t ≥ 5.43) = 1 - P(t < 5.43) = < 0.00001.
The p-value is less than α so the decision is to reject the null hypothesis.
Since the null hypothesis was rejected, then the population average of the penetration of the conduits specimens is greater than 50 mils. It is not recommendable to use these conduits.
I hope it helps!
No, A and B are not independent events
Step-by-step explanation:
Let us study the meaning independent probability
- Two events are independent if the result of the second event is not affected by the result of the first event
- If A and B are independent events, the probability of both events is the product of the probabilities of the both events P (A and B) = P(A) · P(B)
∵ P(A) =
∵ P(B) =
∴ P(A) . P(B) = ×
∴ P(A) . P(B) =
∴ P(A) . P(B) =
∵ P(A and B) =
∵ P(A) . P(B) =
- The two answers are not equal
∴ P (A and B) ≠ P(A) · P(B)
- In independent events P (A and B) = P(A) · P(B)
∴ A and B are not independent events
No, A and B are not independent events
Learn more:
You can learn more about probability in brainly.com/question/13053309
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