Show that Cov(X, Y 1 Z) 5 Cov(X, Y) 1 Cov(X, Z). b. Let X1 and X2 be quantitative and verbal scores on one aptitude exam, and let Y1 and Y2 be corresponding scores on another exam. If Cov(X1, Y1) 5 5, Cov(X1, Y2) 5 1, Cov(X2, Y1) 5 2, and Cov(X2, Y2) 5 8, what is the covariance between the two total scores X1 1 X2 and Y1 1 Y2

Answer:

[tex] {r}^{2} - 4s + {s}^{2} = 8r + 2s = 28 \\ \\ r = \frac{24}{5 } - i \frac{ \sqrt[4]{129} }{5} \\ \: s = \frac{58}{5} + i \frac{ \sqrt[2]{129} }{5 } \\ \\ r = \frac{24}{5} + i \frac{ \sqrt[4]{129} }{5} \\ s = \frac{58}{5} - i \frac{ \sqrt[2]{129} }{5} [/tex]

Answer:

   =(s^2 - t^2)/4

Step-by-step explanation:

a + b = s and a - b = t,

Add the two equations together

a + b = s

a - b = t

----------------

2a = s+t

a = (s+t)/2

Subtract the two equations

a + b = s

- a + b = -t

-------------------

2b =(s-t)

b = (s-t)/2

We want to find ab

ab = (s+t)/2 *  (s-t)/2

FOIL

    =(s^2 - t^2)/4

Answer:

(0 ; 3)

Step-by-step explanation:

hello :

the midpoint of the line segment is : ((-2+2)/2 ;(-2+8)/2 )

(0 ; 3)

Answer:

1/425

Step-by-step explanation:

The first card can be any card, so we don’t have to evaluate the probability.

Now we can suppose that the exit card is a two

- For the second card we have 3/51 of possibilities that is a 2 = 1/17

- For the third card we have 2/50 of possibilities that is a 2 = 1/25

1/17 * 1/25 = 1/425

Hello!

1) 6/10 × 10/6 × 5/9 = 1/10 × 10 × 5/9 = 1 × 5/9 = 5/9 or 0,5

2) 6/10 × 4/3 × 10/20 = 6 × 4/3 × 1/20 = 2 × 4 × 1/20 = 2 × 1/5 = 2/5 or 0,4

Good luck! :)

Answer:

1) 5/9

2) 2/5

Explanation:

1) 6/10 × 10/6 × 5/9=

Multiply all the denominators and all the numerators then simplify= 300/540 = 5/9

2)  6/10 × 4/3 × 10/20=

Multiply all the denominators and all the numerators then simplify= 240/600 = 2/5

Answer:

3.564 m^2

Step-by-step explanation:

The area of the original garden is

A = 5.4 * 1.5 = 8.1

The new garden is

5.4*1.2 = 6.48 by 1.5*1.2 =1.8

The area is

A = 6.48*1.8=11.664

The increase in area is

11.664-8.1=3.564

The given information is,

To find the increase in area of the garden.

Formula we use,

→ Area = Length × Width

Area of the real garden is,

→ 5.4 × 1.5

→ 8.1 m

The new garden will be,

→ 5.4 × 1.2 = 6.48 m

→ 1.5 × 1.2 = 1.8 m

The area of the new garden is,

→ 6.48 × 1.8

→ 11.664

Then the increase in area of the garden,

→ 11.664 - 8.1

→ 3.564 m²

Hence, 3.564 m² is the increase in area.

Answer:

Assessing the association between supplemental vitamin A exposure and mortality and morbidity for measles:

Regarding the relative risk, the correct statement is:

a. Exposure to vitamin A appears to protect against morbidity and mortality for measles.

Step-by-step explanation:

Relative risk for incidence of measles = 0.75

Relative risk for measles mortality = 0.5

Relative risk for mortality and morbidity for measles = 0.375 (0.75 * 0.5)

The combined relative risk is less than 50%

The association is weak because RR is less than 1.

Therefore, there is no association between supplemental vitamin A exposure and mortality and morbidity for measles.

Answer:

The greatest possible value of xy is 165.

Step-by-step explanation:

Answer:

0.5679

Step-by-step explanation:

From. The table Given above :

The probability of female Given an advanced degree ;

P(F|A) = p(FnA) / p(A)

From the table, p(FnA) = 322

P(Advanced degree), P(A) = (245 + 322) = 567

Hence,

P(F|A) = p(FnA) / p(A) = 322 / 567 = 0.5679

Answer:

2 = x          -7 = x

Step-by-step explanation:

f(x) = (x - 2)(x + 7)

y  = (x - 2)(x + 7)

Set y = 0

0 = (x - 2)(x + 7)

Using the zero product property

0 = x-2    0 = x+7

2 = x          -7 = x

Answer:

Zeros happen when f(x) = 0. There are two zeros in the given function:

Therefore solve both equations above and you'll get:

Answer:

See Explanation

Step-by-step explanation:

Given

Let

[tex]s \to Strawberry[/tex]

[tex]b \to Banana[/tex]

So:

[tex]s:b = 2:3[/tex]

Required

Complete the table

The table, to be complete, is not given; so, I will generate one myself.

The table is generated as follows:

Multiply by 1.5

[tex]s : b = 3 : 4.5[/tex]

Multiply by 2

[tex]s : b = 2*2 : 2 * 3[/tex]

[tex]s : b = 4 : 6[/tex]

And so on....

In summary, whatever factor is multiplied to S must be multiplied to B

Answer:

3:8

Step-by-step explanation:

i will gadit

that only

Answer:

0.706....

Step-by-step explanation:

Answer:

below

Step-by-step explanation:

A AND C is the right option

congruent angles are angles with exactly the same measure

Answer:

A, B, and E apply

Step-by-step explanation:

One thing we can do is to make everything in the same format, under one square root, with no non-square roots.

First, we can say that 6 is equal to √36 as 6² =36, and 6 ≥ 0. Therefore, 6√3 = √36 * √3 = √108

For A, √3 * √36 = √108, so this applies

For B, √18 * √6 = √108, so this applies

For C, 108² = √something bigger than 108 = √11664, so this does not apply

For D, √54 ≠ √108, so this does not apply

For E, √108 = √108, so this applies

For F, √3 * √6 = √18, so this does not apply

Answer:

x=2

y=3

Step-by-step explanation:

y=−2x+7

y=5x−7

Set the two equations equal since they are both equal to y

−2x+7 =5x−7

Add 2x to each side

-2x+7+2x = 5x-7+2x

7 = 7x-7

Add 7 to each side

7+7 = 7x-7+7

14 =7x

Divide by 7

14/7 = 7x/7

2 =x

Now find 7

y = 5x-7

y = 5(2) -7

y = 10-7

y = 3

Given that y=y=y,

→ -2x+7 = 5x-7

Let's find the value,

→ -2x+7 = 5x-7

→ 7 = 5x+2x-7

→ 7 = 7x-7

→ 7+7=7x

→ 14 = 7x

→ x = 14/7

→ [x = 2]

Then we can find 7,

→ y = 5x-7

→ y = 5(2) -7 y = 10-7

→ [y = 3]

This is required answer.

Answer:

The number of newborns who weighed between 1614 grams and 5182 grams was of 586.

Step-by-step explanation:

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

The mean weight was 3398 grams with a standard deviation of 892 grams.

This means that [tex]\mu = 3398, \sigma = 892[/tex]

Proportion that weighed between 1614 and 5182 grams:

p-value of Z when X = 5182 subtracted by the p-value of Z when X = 1614.

X = 5182

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{5182 - 3398}{892}[/tex]

[tex]Z = 2[/tex]

[tex]Z = 2[/tex] has a p-value of 0.9772

X = 1614

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{1614 - 3398}{892}[/tex]

[tex]Z = -2[/tex]

[tex]Z = -2[/tex] has a p-value of 0.0228

0.9772 - 0.0228 = 0.9544.

Out of 614 babies:

0.9544*614 = 586

The number of newborns who weighed between 1614 grams and 5182 grams was of 586.

Answer:  Choice B)  [tex]\sqrt{2}[/tex]

Work Shown:

[tex]\sec^2(\theta) = \tan^2(\theta) + 1\\\\\sec^2(\theta) = (\tan(\theta))^2 + 1\\\\\sec^2(\theta) = (-1)^2 + 1\\\\\sec^2(\theta) = 2\\\\\sec(\theta) = \sqrt{2}\\\\[/tex]

Note: secant is positive in quadrant Q4, when theta is between 3pi/2 radians and 2pi radians (270 degrees and 360 degrees). So that's why we don't consider the minus form of the plus minus.

Answer:

10 + 8 + 10 + 10 + 10 + 10 + 8 + 8 + 6 + 6

Answer:

It took Chau 5 hours, 52 minutes, and 30 seconds to clean both rooms.

Step-by-step explanation:

Given that Chau took 5 3/8 hours to clean the bedroom, and then he took a 1/2 to clean the den, to determine how much total time did he take to clean two rooms the following calculation must be performed:

5 + 3/8 + 1/2 = X

5 + 0.375 + 0.5 = X

5.875 = X

0.875 = 7/8

60/8 x 7 = 52.5

Therefore, it took Chau 5 hours, 52 minutes, and 30 seconds to clean both rooms.

Answer:

8

Step-by-step explanation:

Solution :

Group   Before     After

Mean    693.75    743.75

Sd         155.37     143.92

SEM        54.93     50.88

n              8            8

Null hypothesis : The preparation course not effective.

[tex]$H_0: \mu_d = 0$[/tex]

Alternative hypothesis : The preparation course is effective in improving the exam scores.

[tex]$H_a : \mu_d>0$[/tex]  (after -  before)

Step-by-step explanation:

D. RAMONA SAVED THE MOST IN 2006

D. Ramona saved the most in 2006

The three modes are 5, 12, and 150 since they occur the most times and they tie one another in being the most frequent (each occurring 3 times).

Only the 7 and 8 occur once each, and aren't modes. Everything else is a mode. It's possible to have more than one mode and often we represent this as a set. So we'd say the mode is {5, 12, 150} where the order doesn't matter.

(4) y = (3 - 2x)³ + 24x

Use the power and chain rules:

dy/dx = 3 (3 - 2x)² d/dx [3 - 2x] + 24

dy/dx = 3 (3 - 2x)² (-2) + 24

dy/dx = -24x ² + 72x - 30

(5) y = 54x - (2x - 7)³

Same basic procedure:

dy/dx = 54 - 3 (2x - 7)² d/dx [2x - 7]

dy/dx = 54 - 3 (2x - 7)² (2)

dy/dx = -24x ² + 168x - 240

Answer:

Step-by-step explanation:

There are no statements provided, but since it is modeled after the linear function y = mx + b, it is a line. m is the slope or rate of change (which is constant; that's what makes this a line!), and b is the y-intercept (the value of y when x is equal to 0). Its slope is 4 (the function raises 4 units for every 1 unit it moves to the right). Its y-intercept is 8, having the coordinate (0, 8).

Answer:

y = 4x + 8 is a linear function.

Step-by-step explanation:

No statements are given, but here's why:

- It's in slope-intercept form, y = mx + b.

- It has a constant slope.

- A non-linear function does not have a constant slope, and this one does.

Answer:

The probability would be 1/8.

Step-by-step explanation:

The probability of the spinner landing on an odd number is 1/2, and the probability of the spinner landing on a number greater than 8 is 1/4. So we multiply those two probabilites to get our answer 1/8.

Answer:

The 99% confidence interval for the difference in the two proportions is (-0.0247, 0.2833).

Step-by-step explanation:

Before building the confidence interval, we need to understand the Central Limit Theorem and subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

A BYU-Idaho professor took a survey of his classes and found that 82 out of 90 people who had served a mission had personally met a member of the quorum of the twelve apostles.

This means that:

[tex]p_S = \frac{82}{90} = 0.9111[/tex]

[tex]s_S = \sqrt{\frac{0.9111*0.0888}{90}} = 0.045[/tex]

Of the non-returned missionaries that were surveyed 86 of 110 had personally met a member of the quorum of the twelve apostles.

This means that:

[tex]p_N = \frac{86}{110} = 0.7818[/tex]

[tex]s_N = \sqrt{\frac{0.7818*0.2182}{110}} = 0.0394[/tex]

Distribution of the difference:

[tex]p = p_S - p_N = 0.9111 - 0.7818 = 0.1293[/tex]

[tex]s = \sqrt{s_S^2+s_N^2} = \sqrt{0.045^2+0.0394^2} = 0.0598[/tex]

Calculate a 99% confidence interval for the difference in the two proportions.

The confidence interval is:

[tex]p \pm zs[/tex]

In which

z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].

99% confidence level

So [tex]\alpha = 0.01[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.01}{2} = 0.995[/tex], so [tex]Z = 2.575[/tex].

The lower bound of the interval is:

[tex]p - zs = 0.1293 - 2.575*0.0598 = -0.0247[/tex]

[tex]p + zs = 0.1293 + 2.575*0.0598 = 0.2833[/tex]

The 99% confidence interval for the difference in the two proportions is (-0.0247, 0.2833).

Answer: 332 cubic inches

Step-by-step explanation:

You can eliminate 69 and 99 as those answers don't make any sense. This leaves you with 703 and 332.

It says the wall of the pipe is 1.25 inches thick so you multiply that by 2 and subtract it by the diameter to get the insider diameter of 5.5

Now you just use the equation V = (3.14)(r^2)(14) where the radius is half of 5.5.

So to finalize the equation you get V = (3.14)(5.5)^2(14) which comes out to 332 cubic inches

The best choice is 332 cubic inches.

69 cubic inches and 99 cubic inches are less and 703 cubic inches is a large approximation.

Diameter = d= 8 inches

Height= Length = l= 14 inches

Thickness= 1.25 inches

Outer Radius= R= diameter/2= 8/2=4 inches

Inner radius = r= Radius - thickness

                            = 4- 1.25= 2.75 inches

Volume of the cylinder = Area × length

                                      = π r²× l

                                       = 22/7 × (2.75)² × 14

                                          = 332. 616 inches cube

So the best answer is 332 cubic inches

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