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A normally distributed random variable with mean 4.5 and standard deviation 7.6 is sampled to get two independent values, X1 and

mr Goodwill [35]

Answer:

Bias for the estimator = -0.56

Mean Square Error for the estimator = 6.6311

Step-by-step explanation:

Given - A normally distributed random variable with mean 4.5 and standard deviation 7.6 is sampled to get two independent values, X1 and X2. The mean is estimated using the formula (3X1 + 4X2)/8.

To find - Determine the bias and the mean squared error for this estimator of the mean.

Proof -

Let us denote

X be a random variable such that X ~ N(mean = 4.5, SD = 7.6)

Now,

An estimate of mean, μ is suggested as

$\mu = \frac{3X_{1} + 4X_{2} }{8}$

Now

Bias for the estimator = E(μ bar) - μ

= $E( \frac{3X_{1} + 4X_{2} }{8}) - 4.5$

= $\frac{3E(X_{1}) + 4E(X_{2})}{8} - 4.5$

= $\frac{3(4.5) + 4(4.5)}{8} - 4.5$

= $\frac{13.5 + 18}{8} - 4.5$

= $\frac{31.5}{8} - 4.5$

= 3.9375 - 4.5

= - 0.5625 ≈ -0.56

∴ we get

Bias for the estimator = -0.56

Now,

Mean Square Error for the estimator = E[(μ bar - μ)²]

= Var(μ bar) + [Bias(μ bar, μ)]²

= $Var( \frac{3X_{1} + 4X_{2} }{8}) + 0.3136$

= $\frac{1}{64} Var( {3X_{1} + 4X_{2} }) + 0.3136$

= $\frac{1}{64} ( [{3Var(X_{1}) + 4Var(X_{2})] }) + 0.3136$

= $\frac{1}{64} [{3(57.76) + 4(57.76)}] } + 0.3136$

= $\frac{1}{64} [7(57.76)}] } + 0.3136$

= $\frac{1}{64} [404.32] } + 0.3136$

= $6.3175 + 0.3136$

= 6.6311

∴ we get

Mean Square Error for the estimator = 6.6311

6 0

3 years ago

Select all the expressions that are rational numbers.

fredd [130]

..........The answer is D

3 0

3 years ago

bill is replacing his 15ft long by 12 ft wide deck. his new deck will add 5 feet to the length and 4 feet to the width. if a dra

Ira Lisetskai [31]

The dimensions i.e. length and width of the deck in the drawing is 8 and 6.4 inches respectively.

Given that the length of the previous deck = 15 feet

The width of the previous deck = 12 feet

Since the new deck will add 5 feet to the length and 4 feet to the width,

The length of the new deck = 15 + 5 = 20 feet

The width of the new deck = 12 + 4 = 16 feet

Also given that a drawing of the new deck uses a scale of 1 inch = 2.5 feet.

So, The length of the deck in the drawing = 20/2.5 inches = 8 inches

The width of the deck in the drawing = 16/2.5 inches = 6.4 inches

Therefore, the dimensions i.e. length and width of the deck in the drawing is 8 and 6.4 inches respectively.

Learn more about length here -

brainly.com/question/14782156\

#SPJ10

7 0

2 years ago

Math. please help me!!!

d1i1m1o1n [39]

Part A.

In this part we have to find the increasing interval .

Increasing interval is that interval where graph goes up. And from the graph we can say that the graph goes up in the interval

$(-1,0)U (1, \infty)$

And that's the increasing interval .

Part B.

Correct option is B

x and y intercepts

x intercept is the point where graph touches the x axis. And the graph touches the x axis at x=-1 and 1 .

So the x intercepts are

$(-1,0) ,(1,0)$

y intercepts are the point, where the graph touches or crosses the y axis.

Therefore the y intercept is (0,1)

So the correct option is D .

4 0

3 years ago

Read 2 more answers

Find the value of x in the equation 3/4 (8x -6 )-2 = 1/2 (1-2x)

mezya [45]

I continue in comment

7 0

3 years ago

Read 2 more answers