pls help for both 12 and 13!!

Answer:

a.) a = -34 and b = 2

b.) a = -91.11 b = 2.22

c.) David scored 124, nancy scored 84.27

David scored higher

Step-by-step explanation:

for those in the 3rd grade

mean u = 67

s = 10

we used the z formula

[tex]z=\frac{x-u}{s}[/tex]

[tex]z=\frac{x-67}{10}[/tex]

we have the new score

u = 100

s = 20

we use this formula [tex]z*s+u[/tex]

[tex][\frac{x-67}{10} ]20\\[/tex] + 100

multiply through by 20

[tex][\frac{20x-1340}{10} ] +100[/tex]

dividing the bracket by 10

= [tex]2x-134+100[/tex]

= [tex]2x-34[/tex]

from this solution above,

a = -34 and b = 2

b.)

we solve for those in the 6th grade

u = 86

s = 9

[tex]\frac{x-86}{9}[/tex]

for new score,

y = 100

s = 20

[tex][\frac{x-86}{9} ]20+100[/tex]

[tex]2.22x-191.11+100\\= 2.22x - 91.11[/tex]

from this solution

a = -91.11

b = 2.22

c.) if David scored 79

[tex]= 2(x)-34[/tex]

= 2(79) - 34

= 158 - 34

= 124

if nancy scored 79

= 2.22(79) - 91.11

= 175.38 - 91.11

= 84.27

from these scores we can see that David scored higher in his grade

Answer:

g + 200 - 2*600 = 1400

g = 2400 pounds

Step-by-step explanation:

g + 200 - 2*600 = 1400

g + 200 - 1200 = 1400

g - 1000 = 1400

g = 2400

Answer: A

Step-by-step explanation: Ape x

Answer: The cost of adult ticket is $6.1 and that of student ticket is $2.44

Step-by-step explanation:

Let the cost of adult ticket be 'x' and cost of student ticket be 'y'

From the question, the equations formed are:

[tex]662.5=85x+65y[/tex]                .....(1)

[tex]x=2.5y[/tex]                                ......(2)

Putting value of 'y' from equation 2 to equation 1:

[tex]662.5=85(2.5x)+65y\\\\662.5=271.5y\\\\y=\frac{662.5}{271.5}=\$ 2.44[/tex]

Now, solving for 'x', we get:

[tex]x=2.5(2.44)=\$ 6.1[/tex]

Hence, the cost of adult ticket is $6.1 and that of student ticket is $2.44

Answer:

210

Step-by-step explanation:

7:5

First add the ratios

7+5=12

Put each ratio over the denominator 12 then multiply each by the total

7/12×1260= 735

5/12 × 1260 = 525

To find how many more winners than losers

735-525= 210

Answer:

a) 0.9998

b) 0.9979

c) 0.7

d) 0.9155

Step-by-step explanation:

P( people who wear their ties tightly ) = 0.3

P( people who do not wear their ties tightly ) = 1 - 0.3 = 0.7

sample size ( n ) = 30

Given that the events are independent and there are only two outcomes we will apply Binomial distribution

a) P( at least one tie is too tight )

P ( x ≥ 1 ) = 1 - P ( x < 1 ) = 1 - P ( x = 0 )

       = 1 - 0.00002 = 0.9998 ( excel function: 1 - BINOMDIST(0,30,0.3,0) )

b) P( more than two ties are too tight )

P ( x > 2 ) = 1 - P ( x ≤ 2 ) = 1 - BINOMDIST(2, 30, 0.3, 1 )

                                       = 1 - 0.002113178

                                       = 0.9979

c) P ( no tie is tight )

P ( x = 0 ) = 0.7

d) P( at least 18 ties are not too tight )    i.e. ( P = 0.7 )

   P ( x ≥ 18 ) = 1 - P( x ≤  17 )

                     = 1 - BINOMDIST ( 17, 30, 0.7, 1 )

                     = 1 -  0.08447006

                    = 0.9155

PA BRAINLIEST

Answer:

The mean time between logons is of 0.3333 minutes.

Step-by-step explanation:

Poisson process with an average of 3 logons per minute.

This means that the time between logons follows an exponential distribution, which mean is given by:

[tex]E(X) = \frac{1}{\lambda}[/tex]

For this question, we have that [tex]\lambda = 3[/tex], and thus:

[tex]E(X) = \frac{1}{\lambda} = \frac{1}{3} = 0.3333[/tex]

The mean time between logons is of 0.3333 minutes.

Answer:

(x, y) = (-2,-5)

Step-by-step explanation:

Multiply the first equation by 3,and multiply the second equation by 1.

3(3x+y=−11)

1(4x−3y=7)

Becomes:

9x+3y=−33

4x−3y=7

Add these equations to eliminate y:

13x=−26

Then solve13x=−26for x:

13x=−26

13x

13

=

−26

13

(Divide both sides by 13)

x=−2

Now that we've found x let's plug it back in to solve for y.

Write down an original equation:

3x+y=−11

Substitute−2forxin3x+y=−11:

(3)(−2)+y=−11

y−6=−11(Simplify both sides of the equation)

y−6+6=−11+6(Add 6 to both sides)

y=−5

Answer:

x=−2 and y=−5

Answer:

Area of front and back = 2 * 2 * 5 = 20 cm^2

Area of sides = 2 * 3 * 4 = 24 cm^2

Area of top and bottom = 2 * 4 * 5 = 40 cm^2

TOTAL area = 84 cm^2

Step-by-step explanation:

Answer:

a

Step-by-step explanation:

yes

Answer:

[tex]\text{A. }y=1.30x+1.50[/tex]

Step-by-step explanation:

The two ringtones will cost her a total of [tex]0.75\cdot 2=1.50[/tex] and is a fixed amount. The relationship between the cost and number of songs only is [tex]y=1.30x[/tex] and therefore the answer is [tex]\boxed{\text{A. }y=1.30x+1.50}[/tex]. You can also directly find the answer by finding the y-intercept (in this case [tex]1.50[/tex]), as no other answer choices include the term [tex]1.50[/tex], so A must be the correct answer.

Set up a ratio:

16/12 = 28/?

Cross multiply:

16? = 12 x 28

16? = 336

Divide both sides by 16:

? = 336/16

? = 21

Answer:

EF=4

Step-by-step explanation:

vì diện tích bằng nhau và bằng 28 áp dụng công thức tính diện tích

9514 1404 393

Answer:

Step-by-step explanation:

The angle shown is 75°. It is less than 90°, so is an acute angle. (The diagram is misleading in that respect.)

__

The two marked angles are vertical angles, so have the same measure.

  3x° = 75°

  x = 25 . . . . . . . . divide both sides by 3°

Answer:

The 95% confidence interval for the population proportion of people in New Hampshire with cholesterol levels over 200 is (0.3216, 0.4784).

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

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

You are told that a random sample of 150 people from Manchester New Hampshire have been given cholesterol tests, and 60 of these people had levels over the "safe" count of 200.

This means that [tex]n = 150, \pi = \frac{60}{150} = 0.4[/tex]

95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

The lower limit of this interval is:

[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4 - 1.96\sqrt{\frac{0.4*0.6}{150}} = 0.3216[/tex]

The upper limit of this interval is:

[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.4 + 1.96\sqrt{\frac{0.4*0.6}{150}} = 0.4784[/tex]

The 95% confidence interval for the population proportion of people in New Hampshire with cholesterol levels over 200 is (0.3216, 0.4784).

9514 1404 393

Answer:

  about 0.299 kg/m³

Step-by-step explanation:

Density is the ratio of mass to volume.

  ρ = M/V

  ρ = (10 kg)/(4/3π(2 m)³) = 15/(16π) kg/m³ ≈ 0.299 kg/m³

Answer:

The + 78 :-  it should be + 60.

Step-by-step explanation:

Long division:-

x - 3 )4x^4 - 6x^3 + 0x^2 + 6x + 3 ( 4x^3 + 6x^2 + 18x + 60 <--- Quotient.

         4x^4 - 12x^3

                      6x^3 + 0x^2

                       6x^2 - 18x^2

                                   18x^2 + 6x

                                    18x^2 - 54x

                                                 60x + 3

                                                  60x - 180

                                                              183

Step-by-step explanation:

1) -5n+10n

= 5n

2) -x-9+2x-10

= 2x-x-9-10

= x-19

3) -5(x-10)-x

= -5x+50-x

= -6x+50

4) 9-5(1-7x)

= 9-5+35x

= 35x+4

5) y^2-x

= 3^2-2

= 9-2

= 7

Do the remain questions by yourself, you can do it!

Answer:

1) (0,a)

Step-by-step explanation:

f(0) = a. b^0 = a. 1 = a

=> (0,a)

Answer:

3/10 30%.3

hooe its write

Answer:

x<7

Step-by-step explanation:

See image below:)

Answer:

3

Step-by-step explanation:

The perimeter of the rectangle is equal to the doubled sum of the sides, and the area is equal to the product of the sides. So we have the following equation

Answer:

20%

Step-by-step explanation:

Given that

The car is depreciated at a rate of 7% per year

We need to find out the percentage when the car is depreciated after 6 years

So,

Since the car is depreciated by 7% so we can say it can be 0.93 times in a year

Now after 6 years, it would make

= 0.93^3

= 0.80

So, the percentage is

= 1 - 0.80

= 0.20

= 20%

Answer:

The graph of an even function is symmetric about the y-axis. The graph of an odd function is symmetric about the x-axis. It is possible that the use of these two words originated with the observation that the graph of a polynomial function in which all variables are to an even power is symmetric about the y -axis.

Answer:

153.86 cm²

Step-by-step explanation:

Area circle = πr²

Area = 3.14 * 7²

Area = 3.14 * 49

Area = 153.86

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

Answer:

A

Step-by-step explanation:

Solution is in this picture.