solve the equation x square - 9+20=0​

Answer:

C

Step-by-step explanation:

If 30% of the entire population of students are seniors, then this will apply to the female population as well. This means that the probability of being a female senior is 30% * 54%=0.3*0.54=0.162=16.2%, or answer choice C. Hope this helps!

Answer:

The test is left - tailed

We cannot reject the organization's claim ( its cheapest screens will truly last less than 2.8 years)

Step-by-step explanation:

Sample size, n = 61

Sample mean, [tex]\bar{X} = 2.4[/tex]

Standard deviation, [tex]\sigma = 0.88[/tex]

Significance level,  α=0.02

Null hypothesis, [tex]H_{o} : \mu = 2.8[/tex]

Alternative hypothesis, [tex]H_{a} : \mu < 2.8[/tex]

It is clearly seen from the alternative hypothesis, that it is a left tailed test. It is not tailed towards the two directions.

Calculate the test statistic:

[tex]Z = \frac{\bar{X} - \mu}{\sigma/\sqrt{n} } \\Z = \frac{2.4 - 2.8}{0.88/\sqrt{61} }\\Z = - 3.55[/tex]

Calculate the P-value:

P(Z < -3.35) = 0.0002

Since (p-value = 0.0002) < (α=0.02), the null hypothesis is rejected.

It can therefore be concluded that the mean of the cheapest screen is less than 2.8 years. i.e. the cheapest screen will last less than 2.8 years

Answer:

The null and alternative hypotheses:

H0: u = 2.8

H1: u < 2.8

This is a left - tailed test.

For test statistics, use the formula:

[tex] Z = \frac{x' - u}{\sigma/ \sqrt{n}} [/tex]

Where,

Mean, u = 2.8

Sample mean,x' = 2.4

Sample size, n = 61

Standard deviation [tex] \sigma [/tex] = 0.88

Significance level = 0.02

[tex] Z = \frac{2.4 - 0.02}{0.88/ \sqrt{61}} =-3.55[/tex]

Test statistics, Z = -3.55

Pvalue:

Pvalue of Z = -3.55 using standard normal table,

NORMSTID(-3.55) = 0.00019

Pvalue = 0.0002

Critical value:

Since this is a left tailed test, the critical value at 0.02 level of significance is:

[tex] Z_\alpha = Z_0_._0_2 = -2.05 [/tex]

Decision: If pvalue is less than level of significance reject null hypothesis H0.

Conclusion:

Since pvalue, 0.00019 is less than level of significance, 0.02, reject null hypothesis, H0.

We conclude that the mean life of the cheapest screen is less than 2.8 years

Answer:

a:b:c = 15:24:100.

Step-by-step explanation:

We need to make the values of b the same in both ratios so we multiply b = 6 by 4/3 to make it 8 and also multiply 25 by 4/3.

6  25 = 8 : 33.33......

So a:b:c = 5:8:33.33...

To convert to whole numbers we multiply by 3:

a:b:c = 15:24:100.

The cube root of a number is the number which when multiplied by itself three times give you the original number. ... The square root of a number is the number which when multiplied by itself twice give you the original number. As an example, the square root of 9 is 3 because 3×3 = 9

Answer:

a) [tex]\sqrt[3]{4096} = 16[/tex]

b) 4096/ 4 = 1024

Step-by-step explanation:

Answer:

2

180 and 360

Step-by-step explanation:

We conclude that the angle of rotational symmetry is 180°.

For any regular shape that has internal angles measuring θ, the angles of rotational symmetry of that figure are:

A = n*θ

Where n is an integer number (different than zero, because that is the trivial case).

For the case of the rectangle not all the sides measure the same thing, we have internal angles of 90° and opposite sides measure the same.

So we only have rotational symmetry for each two internal angles (2*90° = 180°).

So we conclude that the angle of rotational symmetry is 180°.

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Answer:

5/18

Step-by-step explanation:

5/9 times 1/2

5/18

I may be wrong sorry

Answer:

Buying 5 packs of bread rolls and 3 packs of burger meat

Step-by-step explanation:

Sara needs to find the least common multiple between 6 bread rolls and 10  pieces of burger meat:

[tex]LCM:\\10\ 6\ |2\\5\ \ 3\ |3\\5\ \ 1\ |5\\1\ \ 1\ |1\\\\LCM = 2*3*5=30[/tex]

Sara will get the same amount of burger to bread rolls when she buys 30 units of each. The numbers of packs of each product that she must buy are:

[tex]B=\frac{30}{6}=5\ packs\\ M=\frac{30}{10}=3\ packs[/tex]

Sara should buy 5 packs of bread rolls and 3 packs of burger meat.

Answer:A point can represent a piece of data or an (x,y) value.

Step-by-step explanation:

Answer:

12

Step-by-step explanation:

Answer: 20 inches

Step-by-step explanation:

From the question, a television screen has a length of 15 inches while the diagonal of the TV is 25 inches. To calculate the width, we will use the hypoteneous rule.

Hypotenuse² = length² + width²

25² = 15² + width²

width² = 25² - 15²

width² = 625 - 225

width² = 400

width = ✓400

width = 20

The width of the TV is 20 inches.

Answer:

Vertical: 2 units down

Horizontal: 1 unit left

Step-by-step explanation:

X +/- numbers: means it will go up or down

If its parentheses then it is the opposite

Answer:

C, A and B

Step-by-step explanation:

Tank A holds 40 Liters and 5 fish.

Tank B holds 100 Liters and 12 fish.

Tank C holds 180 Liters and 23 fish.

Therefore, the volume per fish from least to greatest is:

7.83, 8 and 8.33

These correspond to the tanks: C, A and B respectively.

Answer:

CAB

Step-by-step explanation:

Got it right in Khan!

Answer:

5 dollars

Step-by-step explanation:

If the price is 90 % off, we will pay 100 - 90 or 10 %

Take the original price times 10 %

50 * 10 %

50 * .10

5

Answer: 4:5

Step-by-step explanation:

Answer:

The answer for this question is (-3.5,0.5)

Answer:

9/22

Step-by-step explanation:

They are 30 25-fils coins, 25 10-fils coins, 40  5-fils coins and 15 1-fils coins.

The total number of fils coins = 30 + 25 + 40 + 15 = 110 coins

The probability of picking n-fils coin = number of n fils coin /  total number of fils coins.

Therefore:

The probability of picking 25-fils coin = number of 25 fils coin /  total number of fils coins = 30/110 = 3/11

The probability of picking 10-fils coin = number of 10 fils coin /  total number of fils coins = 25/110 = 5/22

The probability of picking 5-fils coin = number of 5 fils coin /  total number of fils coins = 40/110 = 4/11

The probability of picking 1-fils coin = number of 1 fils coin /  total number of fils coins = 15/110 = 3/22

The probability that the first coin  he picks is a 25-fils coin or a 1-fils coin = The probability of picking 25-fils coin + The probability of picking 1-fils coin = 3/11 + 3/22 = 9/22

Answer:

A (-2, 10)

Step-by-step explanation:

If you plug in the point into x and y you should get "false" on a calculator, or the answer won't make sense, meaning that it's not a part of the set

(-2,10) is not the solution set of the given equation [tex]3y+2 =x^{2} -5x+17[/tex].

The solution, or root, of an equation is any value or set of values that can be substituted into the equation to make it a true statement.

According to the given question

We have an equation

[tex]3y + 2 =x^{2} -5x+17[/tex]

The above equation can be written as

[tex]x^{2} -5x +17-3y-2=0...(i)[/tex]

For finding the point which is not the solution set of the equation, first we will substitute the given points in the above equation and check whether it making the equation true or not.

For point (-2, 10)

Substitute, x = -2 and y = 10 in the equation (i)

[tex](-2)^{2} -5(-2) + 17 - 3(10) -2\\=4+10+17-30-2\\= -1\neq 0[/tex]

Hence, (-2, 10) is not the solution of the given equation.

For point (5, 5)

Substitute, x = 5, and y = 5 in equation (i)

[tex](5)^{2} -5(5)+17-3(5)-2\\=25-25+17-15-2\\=0[/tex]

Hence, (5, 5) is the solution of the given equation.

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Answer:

rotation then translation

Based on the information given regarding the triangle, the transformations that can be used to map △RST onto △VWX is D. rotation, then translation.

It should be noted that a congruent triangle simply means when two triangles have the same sides and the same angles.

Since Triangle RST can be rotated about point S and then shifted down and to the left to form triangle VWX, the transformations that can be used to map △RST onto △VWX is rotation, then translation.

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Answer:

A

Step-by-step explanation:

Answer:

3 1/7 units

Step-by-step explanation:

(im assuming that 22/7 is what it's being converted here lol) basically what you would do is turn this in to a mixed fraction. You look at how many sevens can go into 22. In this case, three "sevens" would go into 22 (7x3=21). Since we have one left over, it would go over the 7! So that final answer would be 3 1/7!

Answer:

15%

Step-by-step explanation:

Answer:

15%

Step-by-step explanation:

[tex]\frac{99}{660} =\\\\\frac{3}{20} =\\\\\frac{15}{100}[/tex]

99 is 15% of 660

Answer:

$68.40

Step-by-step explanation:

Let x represent the required cost.

Since the number of toys is directly proportional to the cost:

x : $20.52 = 120 : 36

i.e.  x/$20.52 = 120/36

      x = ([tex]\frac{120 * $20.52}[/tex])/36

      x = $2462.40/36

      x = $68.40

Hope this helps!!!

Answer:

x = ±11

Step-by-step explanation:

x^2 = 121

Take the square root of each side

sqrt(x^2) = ±sqrt(121)

x = ±11

Answer:

k= [tex]\frac{x^{2}+6 }{2x}[/tex]

Step-by-step explanation:

x(x−2k)+6=0

Step 1: Add -x^2 to both sides.

−2kx+x2+6+−x2=0+−x2

−2kx+6=−x2

Step 2: Add -6 to both sides.

−2kx+6+−6=−x2+−6

−2kx=−x2−6

Step 3: Divide both sides by -2x.

−2kx /−2x  = −x2−6 /−2x

k =

Answer:

2 + an

Step-by-step explanation:

1 + 1 + na

2 + am

Answer:

D

Step-by-step explanation:

P(A n B) given A and B are independent events is P(A) * P(B)

The probability of intersection of event A and B is 0.135, the correct option is D.

Probability is the study of chance of an event to happen.

A and B are two independent events.

P(A) = 0.3

P(B) = 0.45

P(A ∩ B) = P(A) * P(B)

P(A ∩ B) = 0.3 *0.45

P(A ∩ B) = 0.135

Therefore, the probability of intersection of event A and B is 0.135, the correct option is D.

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Subtract like terms:

3 -4 = -1

8i - 2i = 6i

The answer is -1+6i