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3 years ago

Please help me. 10 pts

Mathematics

2 answers:

mina [271]3 years ago

4 0

The answer to your problem is -2.1.

Goryan [66]3 years ago

3 0

Because it is a negative plus a negative you would take away -1.8 from -.3. you would then get -2.1

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Enter an algebraic equation for the sentence. Use x as your variable.

Kitty [74]

Answer:

5x-4=11

Step-by-step explanation:

so you multiply 5 times x (a number) and subtract 4 and it equals to 11

6 0

3 years ago

Suppose that E(θˆ1) = E(θˆ2) = θ, V(θˆ 1) = σ2 1 , and V(θˆ2) = σ2 2 . Consider the estimator θˆ 3 = aθˆ 1 + (1 − a)θˆ 2. a Show

katen-ka-za [31]

Answer:

Step-by-step explanation:

Given that:

$E( \hat \theta _1) = \theta \ \ \ \ E( \hat \theta _2) = \theta \ \ \ \ V( \hat \theta _1) = \sigma_1^2 \ \ \ \ V(\hat \theta_2) = \sigma_2^2$

If we are to consider the estimator $\hat \theta _3 = a \hat \theta_1 + (1-a) \hat \theta_2$

a. Then, for $\hat \theta_3$ to be an unbiased estimator ; Then:

$E ( \hat \theta_3) = E ( a \hat \theta_1+ (1-a) \hat \theta_2)$

$E ( \hat \theta_3) = aE ( \theta_1) + (1-a) E ( \hat \theta_2)$

$E ( \hat \theta_3) = a \theta + (1-a) \theta = \theta$

b) If $\hat \theta _1 \ \ and \ \ \hat \theta_2$ are independent

$V(\hat \theta _3) = V (a \hat \theta_1+ (1-a) \hat \theta_2)$

$V(\hat \theta _3) = a ^2 V ( \hat \theta_1) + (1-a)^2 V ( \hat \theta_2)$

Thus; in order to minimize the variance of $\hat \theta_3$ ; then constant a can be determined as :

$V( \hat \theta_3) = a^2 \sigma_1^2 + (1-a)^2 \sigma^2_2$

Using differentiation:

$\dfrac{d}{da}(V \ \hat \theta_3) = 0 \implies 2a \ \sigma_1^2 + 2(1-a)(-1) \sigma_2^2 = 0$

⇒

$a (\sigma_1^2 + \sigma_2^2) = \sigma^2_2$

$\hat a = \dfrac{\sigma^2_2}{\sigma^2_1+\sigma^2_2}$

This implies that

$\dfrac{d}{da}(V \ \hat \theta_3)|_{a = \hat a} = 2 \ \sigma_1^2 + 2 \ \sigma_2^2 > 0$

So, $V( \hat \theta_3)$ is minimum when $\hat a = \dfrac{\sigma_2^2}{\sigma_1^2+\sigma_2^2}$

As such; $a = \dfrac{1}{2}$ if $\sigma_1^2 \ \ = \ \ \sigma_2^2$

4 0

4 years ago

Need help on this !!!!!!

grin007 [14]

Answer:

y = 3x + 3

Step-by-step explanation:

y = mx + b where m= slope and b= y-intercept

the y-intercept is the point where x=0 or where the line crosses the y-axis.

This happens at (0,3) on the graph, so the y-intercept, or b, is equal to 3.

for m, slope can be defined as rise/run. So starting from a point you are given on the graph (-1,-2), count the number of spaces up you rise and how many you must go over (run) to get to the next point (0,3)

if you count, you should rise from (-1,-2) 5 spaces and move to the right (run) 1 space to get to (0,3).

rise/run = 3/1

3/1 = 3

the slope is 3.

now that you have the slope and the y-intercept, you can just plug it into the equation

y = 3x + 3

5 0

3 years ago

. 4/18 times 2/92. 1/9 times 3/63. 12/14 times 1/84.1/7 times 5/65. 17/20 times 1/61. 4 1/4 times 3 1/22. 3 5/6 times 4 1/23. 2

AlladinOne [14]

Answer:

Step-by-step explanation:

4/18×2/92

=1/9×1/23

=1/207

1/9×3/63

=1/3×1/23

=1/69

12/14×1/84

=1/14×1/7

=1/98

1/7×5/65

=1/7×1/13

=1/91

17/20×1/61

=17/1220

4 1/4 ×3 1/22

=17/4×67/22

=1,139/88

=12 83/88

3 5/6×4 1/23

=23/6×93/23

=93/6

=15 3/6

=15 1/2

2 1/2×4 7/84

=5/2×343/84

=1715/168

=10 35/168

I have answered more than 2 from each set

6 0

3 years ago

Middle School teaches 6th, 7th, and 8th grade classes. The sixth grade has 318 students, the 7th has 286 students, and the 8th h

Ierofanga [76]

Answer:

$3185

Step-by-step explanation:

Multiply the number of grade 6 students by the money needed ($3.50) and you get 318x3.50=1113

Multiply the number of grade 7 students by the money needed ($3.50) and you get 286x3.50=1001

Multiply the number of grade 8 students by the money needed ($3.50) and you get 306x3.50=1071

Add all the total amounts together and you get $3185

8 0

3 years ago