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Strike441 [17]
2 years ago
10

if two angles are complementary then the sum of their measure is 90. if the sum of the measures of two angles is 90 then both of

the angles are acute.
Mathematics
1 answer:
Tju [1.3M]2 years ago
6 0
Yes, both angles are acute because all complementary angles are acute.
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60 plus 18% ill give brainliest :)
aksik [14]

Answer:

70.8

Step-by-step explanation:

YOU'RE WELCOME

8 0
3 years ago
Let X1,X2......X7 denote a random sample from a population having mean μ and variance σ. Consider the following estimators of μ:
Viefleur [7K]

Answer:

a) In order to check if an estimator is unbiased we need to check this condition:

E(\theta) = \mu

And we can find the expected value of each estimator like this:

E(\theta_1 ) = \frac{1}{7} E(X_1 +X_2 +... +X_7) = \frac{1}{7} [E(X_1) +E(X_2) +....+E(X_7)]= \frac{1}{7} 7\mu= \mu

So then we conclude that \theta_1 is unbiased.

For the second estimator we have this:

E(\theta_2) = \frac{1}{2} [2E(X_1) -E(X_3) +E(X_5)]=\frac{1}{2} [2\mu -\mu +\mu] = \frac{1}{2} [2\mu]= \mu

And then we conclude that \theta_2 is unbiaed too.

b) For this case first we need to find the variance of each estimator:

Var(\theta_1) = \frac{1}{49} (Var(X_1) +...+Var(X_7))= \frac{1}{49} (7\sigma^2) = \frac{\sigma^2}{7}

And for the second estimator we have this:

Var(\theta_2) = \frac{1}{4} (4\sigma^2 -\sigma^2 +\sigma^2)= \frac{1}{4} (4\sigma^2)= \sigma^2

And the relative efficiency is given by:

RE= \frac{Var(\theta_1)}{Var(\theta_2)}=\frac{\frac{\sigma^2}{7}}{\sigma^2}= \frac{1}{7}

Step-by-step explanation:

For this case we assume that we have a random sample given by: X_1, X_2,....,X_7 and each X_i \sim N (\mu, \sigma)

Part a

In order to check if an estimator is unbiased we need to check this condition:

E(\theta) = \mu

And we can find the expected value of each estimator like this:

E(\theta_1 ) = \frac{1}{7} E(X_1 +X_2 +... +X_7) = \frac{1}{7} [E(X_1) +E(X_2) +....+E(X_7)]= \frac{1}{7} 7\mu= \mu

So then we conclude that \theta_1 is unbiased.

For the second estimator we have this:

E(\theta_2) = \frac{1}{2} [2E(X_1) -E(X_3) +E(X_5)]=\frac{1}{2} [2\mu -\mu +\mu] = \frac{1}{2} [2\mu]= \mu

And then we conclude that \theta_2 is unbiaed too.

Part b

For this case first we need to find the variance of each estimator:

Var(\theta_1) = \frac{1}{49} (Var(X_1) +...+Var(X_7))= \frac{1}{49} (7\sigma^2) = \frac{\sigma^2}{7}

And for the second estimator we have this:

Var(\theta_2) = \frac{1}{4} (4\sigma^2 -\sigma^2 +\sigma^2)= \frac{1}{4} (4\sigma^2)= \sigma^2

And the relative efficiency is given by:

RE= \frac{Var(\theta_1)}{Var(\theta_2)}=\frac{\frac{\sigma^2}{7}}{\sigma^2}= \frac{1}{7}

5 0
3 years ago
Which of the following is a a solution to the equation y=3x-1
Burka [1]
For option a, y = 3(4) - 1 = 12 - 1 = 11                  [not correct]
For option b, y = 3(2) - 1 = 6 - 1 = 5                      [correct]

Therefore option b is a solution to the given equation.
6 0
3 years ago
The sum of A and B is 171 and their difference is 35. What are the numbers?
antoniya [11.8K]

Answer:

103 and 68

Step-by-step explanation:

since the difference has to be 35 subtract 35 from 171 (equals 136) then divide it by 2, you get 68 which is your first number, then add 35 back and get 103 for the second number, I hope this helped

3 0
3 years ago
Read 2 more answers
If the circumference of the circle below is 72 what is the length of AB (the minor arc)
xenn [34]

Answer:

2πr=72

=2*22/7*r=72

=r=72*7/44=504/44=252/22=126/11=11.45

=πr theta /180=22/7*11.45*60/180

=11.99=12(approx)

answer is (a) 12

7 0
3 years ago
Read 2 more answers
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