help please i need this now step by step

Answer:

The  number of rainfalls is [tex]n =96[/tex]

The answer to the second question is  no it will not be valid this because from the question we are told that the experiment require one pH reading per rainfall so getting multiply specimens(used for the  pH reading) from  one rainfall will make the experiment invalid.

Step-by-step explanation:

from the question we are told that

    The  standard deviation is  [tex]\sigma = 0.5[/tex]

     The  margin of error is  [tex]E = 0.1[/tex]

Given that the confidence level is  95%  then we can evaluate the level of significance as

                  [tex]\alpha = 100 - 95[/tex]

                  [tex]\alpha = 5 \%[/tex]

                 [tex]\alpha =0.05[/tex]

Next we will obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table , the value is  [tex]Z_{\frac{\alpha }{2} } = 1.96[/tex]

Generally the sample size is mathematically represented as

           [tex]n = [\frac{Z_{\frac{\alpha }{2} * \sigma }}{ E} ]^2[/tex]

substituting values

             [tex]n = [\frac{1.96 * 0.5 }{ 0.1} ]^2[/tex]

            [tex]n =96[/tex]

The answer to the second question is  no the validity is null this because from the question we are told that the experiment require  one pH reading per rainfall so getting multiply specimens(used for the  pH reading) from  one rainfall will make the experiment invalid

Answer:

B. the product of 7 and a number x

Step-by-step explanation:

7x is 7 multiplied by x.

Answer:

b is the product

Step-by-step explanation:

Answer:

x=2y/3

Step-by-step explanation:

Answer:

x = 2y/3

Step-by-step explanation:

5(x + y) = 2x + 7y

5x + 5y = 2x + 7y

5x - 2x = 7y - 5y

3x = 2y

x = 2y/3

Thus, The value of x = 2y/3

Answer:

variables: m ,c

coefficients, 24, 5

terms  24c,5m,19.99

24C represents the cost of the colored pencils

24 packages at a cost of c each

5m represents the cost of the markers

5 packages of markers at a cost of m each

19.99 for the bean bag chair

Step-by-step explanation:

24C + 5m + 19.99

variables: m ,c

coefficients, 24, 5

terms  24c,5m,19.99

24C represents the cost of the colored pencils

24 packages at a cost of c each

5m represents the cost of the markers

5 packages of markers at a cost of m each

19.99 for the bean bag chair

Looks like either [tex]f''(x)=4x^2[/tex] or [tex]f''(x)=\frac4{x^2}[/tex]...

In the first case, integrate both sides twice to get

[tex]f''(x)=4x^2\implies f'(x)=\dfrac43x^3+C_1\implies f(x)=\dfrac13x^4+C_1x+C_2[/tex]

Then the initial conditions give

[tex]f'(1)=2\implies 2=\dfrac43\cdot1^3+C_1\implies C_1=\dfrac23[/tex]

[tex]f(1)=5\implies 5=\dfrac13\cdot1^4+C_1\cdot1+C_2\implies C_2=4[/tex]

so that the particular solution is

[tex]f(x)=\dfrac{x^4}3+\dfrac{2x}3+4[/tex]

If instead [tex]f''(x)=\frac4{x^2}[/tex], we have

[tex]f''(x)=\dfrac4{x^2}\implies f'(x)=-\dfrac4x+C_1\implies f(x)=-4\ln|x|+C_1x+C_2[/tex]

[tex]f'(1)=2\implies 2=-\dfrac41+C_1\implies C_1=6[/tex]

[tex]f(1)=5\implies 5=-4\ln|1|+C_1\cdot1+C_2\implies C_2=-1[/tex]

[tex]\implies f(x)=-4\ln|x|+6x-1[/tex]

Answer:

16 once is the better one.

Answer: 12-ounce bag is better by $0.02 per ounce

Concept:

When coming across questions that ask for a comparison between prices, we should make the final unit [price per object].

In finding [price per object], simply do [Total price / number of objects].

Solve:

A 12-ounce bag of rice costs $4.08

Total price / number of objects = 4.08 / 12 = $0.34 per ounce

A 16-ounce bag of rice costs $5.76

Total price / number of objects = 5.76 / 16 = $0.36 per ounce

$0.36 - $0.34 = $0.02

$0.34 < $0.36, therefore, 12-ounce bag is better by $0.02 per ounce.

Hope this helps!! :)

Please let me know if you have any questions

Answer:

c

Step-by-step explanation:

c. a descriptive technique

Answer:

y= -4/3x+10 2/3

Step-by-step explanation:

To do this, just put the equation in point slope form and then rearrange it to y=mx+b, or slope intercept form. Slope point form is arranged like this, y-y1=m(x-x1). Now, just insert in the variables (x1=x coordinate of point, y1= y coordinate of point, m=slope). So your equation is now y-20=-4/3(x-7), which simplifies to y-20=-4/3x-9 1/3. Now rearrange it so that y in by itself, and all like terms are combined, making it look like this: y=-4/3x+10 2/3. Now its in slope intercept form and you've got your answer.

I hope my explanation wasn't confusing and that my answer helped.

Answer:

-9

Step-by-step explanation:

4 + (-13)

=> 4 - 13

=> -9

Step-by-step explanation:

The limit of a function is the value it approaches.

In #37, as x approaches infinity (far to the right), the curve f(x) approaches 1.  As x approaches negative infinity (far to the left), the curve f(x) approaches -1.

lim(x→∞) f(x) = 1

lim(x→-∞) f(x) = -1

In #38, as x approaches infinity (far to the right), the curve f(x) approaches 2.  As x approaches negative infinity (far to the left), the curve f(x) approaches -3.

lim(x→∞) f(x) = 2

lim(x→-∞) f(x) = -3

Answer:

12

Step-by-step explanation:

Perimeter of a square:

4(L)

L = Length

=> 4(L) = 48

=> 4L = 48

=> 4L/4 = 48/4

=> L = 12

The length of the square is 12 cm.

Answer:

12

Step-by-step explanation:

Since the lengths of the sides of a square are equal, divide the perimeter by 4

Answer:

17) 750/9 and 18) 364

Step-by-step explanation:

17. Summation of 75*(0.1)^i from i=0 to infinity, that is equal to 75*(Summation of (0.1)^i). Summation of (0.1)^I is a geometric series with a sum of 1/(0.9)=10/9. Hence the series have a sum equal to 75*(10/9)=750/9

18) It's a series with sum=1+3+9+27+81+243=364

Answer:

Steven ate 3 pieces

Step-by-step explanation:

If Johnny ate 3/4 , then Steven at 1 - 3/4  or 1/4

12 * 1/4 = 3

Steven ate 3 pieces

Answer:

3 slices of pizza

Step-by-step explanation:

There are 12 total slices of pizza. In order to find how much Johnny ate, we must multiply 12 by 3/4.

12/1 × 3/4 OR 12 × 0.75 = 9

Johnny ate 9 slices of pizza.

Then, we have to subtract 9 from 12 to determine how many slices Steven ate.

12 - 9 = 3

Steven ate 3 slices of pizza.

Answer:

We are given the function:

[tex]f(x)=2x^2-x-10[/tex]

[tex]Here,\\a=2, b=-1,c=-10[/tex]

1. X-intercepts are the points at which the graph of a function intersects or cuts the x-axis. Since the x-intercept always lies on the x-axis, its ordinate or y-coordinate will always be 0. Since the function is quadratic, it will have at most 2 x-intercepts.

In order to find the x intercept, we basically solve for x at y=0:

[tex]f(x)=2x^2-x-10\\As\ y=0,\\0=2x^2-x-10\\2x^2-x-10=0\\ 2x^2-5x+4x-10=0\\x(2x-5)+2(2x-5)=0\\(x+2)(2x-5)=0\\Hence,\\Individually:\\x=-2,\ x=\frac{5}{2}[/tex]

Hence, the x-intercepts of the parabola of f(x) is (-2,0),(2.5,0)

2. The vertex of parabola is determined as maximum or minimum, solely on how it opens. This depends on the nature of the co-efficient of the x^2 term or 'a'. If a is positive the parabola opens upwards (minimum point) and downwards (maximum point) if negative. Hence, here as a=2, the parabola opens upwards and its vertex is minimum.

[tex]Vertex=(\frac{-b}{2a},\frac{-D}{4a})\\Hence,\\D=b^2-4ac\\Substituting\ a=2,b=-1,c=-10:\\D=(-1)^2-4*2*-10=1+80=81\\Hence,\\Vertex\ of\ f(x)=(\frac{-(-1)}{2*2},\frac{-81}{4*2})=(\frac{1}{4},\frac{-81}{8})[/tex]

3. [Please refer to the attachment]

From the graph, we observe that the parabola cuts the x-axis at (-2,0),(2.5,0). Also, its clear that the axis of symmetry passes through [tex](\frac{1}{4},\frac{-81}{8})[/tex], which is its minimum point.

Answer:

A chord of a circle is 9cm long if it's distance from the centre of the circle is 5cm calculate the radius of the circle

Answer:

(x+4)(x-3)

Step-by-step explanation:

x^2+x-12

=x^2+(4-3)x-12

=x^2+4x-3x-12

=x (x+4)-3 (x+4)

=(x+4)(x-3)

Answer:x=6

Step-by-step explanation:

Answer:

its b plz give brainlist

Step-by-step explanation:

Answer:

252 miles

Step-by-step explanation:

19.99 + .80x = 221.59

,80x = 201.60

x = 252

Answer:

[tex]x = -\frac{3}{2}[/tex] or [tex]x = 1[/tex]

Step-by-step explanation:

Using the zero product property, first step is to set the given equation, [tex] 2x^2 + x - 1 = 2 [/tex] , to zero. Then factorise the left side.

Thus,

[tex] 2x^2 + x - 1 = 2 [/tex]

Subtract 2 from both sides

[tex] 2x^2 + x - 1 - 2 = 2 - 2 [/tex]

[tex] 2x^2 + x - 3 = 0 [/tex]

Factorise the left side

[tex] 2x^2 + 3x - 2x - 3 = 0 [/tex]

[tex] x(2x + 3) - 1(2x + 3) = 0 [/tex]

[tex] (x - 1)(2x + 3) = 0 [/tex]

Find the solution

[tex] x - 1 = 0 [/tex]

Or

[tex]2x + 3 = 0[/tex]

[tex] x = 1 [/tex]

Or

[tex]2x + 3 = 0[/tex]

[tex]2x = -3[/tex]

[tex]x = -\frac{3}{2}[/tex]

The answer is: [tex] x = 1 [/tex] or [tex]x = -\frac{3}{2}[/tex]

In domain and range of a relation, if R be a relation from set A to set B, then

• The set of all first components of the ordered pairs belonging to R is called the domain of R.

Thus, Dom(R) = {a ∈ A: (a, b) ∈ R for some b ∈ B}.

• The set of all second components of the ordered pairs belonging to R is called the range of R.

Thus, range of R = {b ∈ B: (a, b) ∈R for some a ∈ A}.

Therefore, Domain (R) = {a : (a, b) ∈ R} and Range (R) = {b : (a, b) ∈ R}

Hey there! I'm happy to help!

When rotating a point 90 degrees clockwise about the origin, our original point (x,y) becomes (-y,x), because it is now at a negative y-value.

We see that our point P is at (1,2). We can use this rotation formula to find the coordinates of P' (the new spot where P is)/

(x,y)⇒(-y,x)

(1,2)⇒(-2,1)

Therefore, the coordinates of the point P' are (-2,1).

Have a wonderful day! :D

Answer: 0.8749

Step-by-step explanation:

Given, The time, X minutes, taken by Tim to install a satellite dish is assumed to be a normal random variable with mean 127 and standard deviation 20.

Let x be the time taken by Tim to install a satellite dish.

Then, the probability that Tim will takes less than 150 minutes to install a satellite dish.

[tex]P(x<150)=P(\dfrac{x-\text{Mean}}{\text{Standard deviation}}<\dfrac{150-127}{20})\\\\=P(z<1.15)\ \ \ [z=\dfrac{x-\text{Mean}}{\text{Standard deviation}}]\\\\=0.8749\ [\text{By z-table}][/tex]

hence, the required probability is 0.8749.

Answer:

the answer is going to be 2/4

Although you said the variance is 120, I suspect you meant to say standard deviation. If that's the case, then

P(970 < x < 1320)

= P((970 - 1250)/120 < (x - 1250)/120 < (1320 - 1250)/120)

≈ P(-2.3333 < z < 0.5833)

= P(z < 0.5833) - P(z < -2.3333)

≈ 0.72012 - 0.009815

≈ 0.7104

If you really did mean variance, then

P(970 < x < 1320)

= P((970 - 1250)/√120 < (x - 1250)/√120 < (1320 - 1250)/√120)

≈ P(-25.5604 < z < 6.3901)

= P(z < 6.3901) - P(z < -25.5604)

≈ 1 - 0

≈ 1

Answer:

[tex](5 - 2y) \div 12 > 1 - 6y[/tex]

[tex]5 - 2y > 12 - 72y[/tex]

[tex] - 7 > - 70y[/tex]

[tex]7 < 70y[/tex]

[tex]y > 1 \div 10 = 0.1[/tex]

Answer:

14/20 or .7 or 70%

Step-by-step explanation:

Total Number of cards: 20

Number of Red cards: 6

The leftover cards: 20 -6 = 14

The probability of not getting a red = 14/20

14/20 as a decimal = 14/20 = 70/100 = .7

14/20 as a percent = 14/20 = 70/100 = 70%

Solve

Let's solve your equation step-by-step.

9x−3−8x=7−x

Step 1: Simplify both sides of the equation.

9x−3−8x=7−x

9x+−3+−8x=7+−x

(9x+−8x)+(−3)=−x+7(Combine Like Terms)

x+−3=−x+7

x−3=−x+7

Step 2: Add x to both sides.

x−3+x=−x+7+x

2x−3=7

Step 3: Add 3 to both sides.

2x−3+3=7+3

2x=10

Step 4: Divide both sides by 2.

2x

2

=

10

2

x=5

Answer:

x=5

Answer:

Hope this is easier, good luck.