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4 years ago

Can the distributive property be used to rewrite 2x(9-6)

Mathematics

1 answer:

KonstantinChe [14]4 years ago

6 0

No. The variable makes it to where you’re unable to multiply 2 by the numbers in the parentheses.

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There are 20 people at a party 2 are best friends. What is the possibility of them both being pretty?

Oliga [24]

I ain’t never seen two pretty best friends, always one of them gotta be ugly

7 0

3 years ago

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

1,220,000,000 in scientific notation? 0.0287 in scientific notation?

ExtremeBDS [4]

Answer:
= 1.22 × 109
(scientific notation)

= 1.22e9
(scientific e notation)

= 1.22 × 109
(engineering notation)
(billion; prefix giga- (G))

= 1220000000
(real number)
_________________________________________________

Answer:
= 2.87 × 10-2
(scientific notation)

= 2.87e-2
(scientific e notation)

= 28.7 × 10-3
(engineering notation)
(thousandth; prefix milli- (m))

= 0.0287
(real number)

6 0

3 years ago

Read 2 more answers

It’s only 10 points but it’s all i got (:

weqwewe [10]

Answer:

Thx a lot

Step-by-step explanation:

4 0

3 years ago

I dont know how to solve this does anybody?

postnew [5]