Researchers have collected data on the hours of studying in a week and the exam grade of a student. You are given the data below. Hours of Studying 1 3 3 3 5 Exam Grade 55 75 80 85 100 (1) Develop the least squares regression equation. (6 points) (2) Estimate the exam grade of a student with 2 hours of studying. (3 points) (3) Compute the coefficient of determination. (6 points) (4) Perform a t test to test whether the exam grade is significantly related to the number of hours of studying with a = 0.01. What is your conclusion? (5 points) (5) Perform an Ftest to test whether the exam grade is significantly related to the

Answer:

x = [tex]\frac{5-3y}{2}[/tex]

Step-by-step explanation:

2x + 3y = 5

isolate variable: 2x = 5-3y

divide by 2: x = [tex]\frac{5-3y}{2}[/tex]

Using a system of equations, the number of seats in the upper section of the racetrack is 3,600.

A system of equations, also called simultaneous equations, is two or more equations solved concurrently.

We can use any of the following methods to solve simultaneous equations:

In this situation, after forming the equations, we can use substitution and elimination methods to solve them.

Racetrack charge per lower seat = $85

Racetrack charge per upper seat = $60

Racetrack charge per field ticket = $35

Let lower seats = x

Let upper seats = 3x

Let field tickets = y

4x + y = 22,800 ... Equation 1

y = 22,800 - 4x ...Equation 3

85x + 60(3x) + 35y = 948,000

85x + 180x + 35y = 948,000 ... Equation 2

Substitute Equation 3 in Equation 2 to eliminate y:

85x + 180x + 35(22,800 - 4x) = 948,000

85x + 180x + 798,000 - 140x = 948,000

125x = 948,000 - 798,000

125x = 150,000

x = 1,200

Determining the number of seats:

Seats in the Lower section = 1,200

Seats in the Upper section = 3,600 (1,200 x 3)

Field tickets, y = 22,800 - 4x

y = 22,800 - 4(1,200)

= 18,000

Check:

85x + 180x + 35y = 948,000

85(1,200) + 180(1,200) + 35(18,000) = 948,000

102,000 + 216,000 + 630,000 = 948,000

948,000 = 948,000

Thus, based on simultaneous equations, there are 3,600 seats in the upper section of the racetrack.

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Part 1

[tex]-4.9t^2 +18.24t+0.8=-1.43t+4.26\\\\-4.9t^2 +19.67t-3.46=0\\\\\Delta =(19.67)^2 -4(-4.9)(-3.46)=319.0929 > 0[/tex]

Therefore, the blocker can knock down the punt.

Part 2

Using the quadratic formula,

[tex]t=\frac{-19.67 \pm \sqrt{319.0929}}{2(-4.9)}\\\\t \approx 0.18437, 3.82992[/tex]

Considering the graphs, it is clear to take the smaller solution. Thus, the point of intersection is [tex](0.18437, h(0.18437))=\boxed{(0.18437, 3.99635)}[/tex].

Standard deviation will be √3.3516 .

To calculate the standard deviation for the given data first we have to calculate the total number of students , mid value , fiXi , fiXi².

After that , we have to calculate the Xbar by using

Xbar = ∑fiXi / N

for which we need the value of fi , Xi and N

N = 100

fiXi = 6478

we have calculated the values from the given data ,

Therefore ,

Xbar = 6478 / 100

= 64.78

Var(X) = αx² - ∑fiXi² / N - (Xbar²)

= 419980 / 100 - (64.78)²

= 4199.80 -4196.4484

=3.3516

Thus,

standard deviation ax = √var(X)

= √3.3516

Therefore , the standard deviation will be  √3.3516

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Answer: The coefficient of the term with t^3 and q^14 in the expansion of (3t - q)^17 is 816 / 3.

Step-by-step explanation: The coefficient of the term with a certain power of t and a certain power of q in the expansion of a binomial raised to a power can be found using the binomial formula. The formula is given by:

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(a + b)^n = sum_{k=0}^n choose(n, k) * a^(n-k) * b^k

In this case, we have a = 3t, b = -q, and n = 17. We want to find the coefficient of the term with t^3 and q^14, which means we need to find the coefficient of the term with a^(n-k) = t^3 and b^k = q^14. Plugging these values into the formula, we get:

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(3t - q)^17 = sum_{k=0}^17 choose(17, k) * 3^(17-k) * (-1)^k * t^(17-k) * q^k

To find the coefficient of the term with t^3 and q^14, we need to find the value of choose(17, k) for k = 3. The binomial coefficient choose(n, k) is equal to the number of ways to choose k items from a set of n items. It can be calculated using the formula:

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choose(n, k) = n! / (k! * (n-k)!)

where n! is the factorial of n, which is the product of all positive integers less than or equal to n. For example, 5! = 5 * 4 * 3 * 2 * 1 = 120.

In our case, we have n = 17 and k = 3, so the coefficient we are looking for is:

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choose(17, 3) = 17! / (3! * (17-3)!) = 17 * 16 * 15 * 14 * 13 * 12 * 11 * 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1 / (3 * 2 * 1 * 14 * 13 * 12 * 11 * 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1) = 17 * 16 / 3 = 816 / 3

Therefore, the coefficient of the term with t^3 and q^14 in the expansion of (3t - q)^17 is 816 / 3.

The solution of the equation written as an imaginary number is y =  3i or -3i

An imaginary number is a number of the form ai, where a is a real number and i is the square root of -1. Imaginary numbers are often denoted with the letter "i".

Given: y² + 11 = 2

y² + 11 = 2

y² = 2 - 11

y² = -9

y = ±√-9                      

y = ± 3i

y = 3i or -3i

(Note: √9 = 3 and √-9 = 3i)

Thus, the solution is y =  3i or -3i

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The correct answer is A) y = 9000x + 65,000.

The correct answer is A) y = 9000x + 65,000.

The house has increased in value by 54,000 ($119,000 - $65,000) over 6 years (change in x), so the slope must be 9000 (54,000/6).

The equation y = 9000x + 65,000

models the value of the house after x years, where y is the value of the house,

9000x is the slope of the equation,

and 65,000 is the y-intercept.

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Least time required to reach the point Q as per the distance and the speed rate is equal to 2 hours.

As given in the question,

Nearest point on the coast is 2 miles far away

rate of the row = 1mile per hour

Walk at the rate of 3 miles per hour

Let 'x' hours be the least time to reach point Q.

Time = distance / speed

Time taken to reach the point Q = [√ 1 + ( 3 - x)² ]/ 3

Time taken to reach the coast = (√ 4 + x² ) / 1

Total  time taken 't' = (√ 4 + x² ) / 1 + [√ 1 + ( 3 - x)² ]/ 3

To find least time dt/dx = 0

t  = (√ 4 + x² ) / 1 + [√ 1 + ( 3 - x)² ]/ 3

⇒dt/dx = [ x / √ 4 + x² ] + ( 3 - x) / √( 10 -6x + x² )

⇒x / √ 4 + x² = ( x - 3) / √( 10 -6x + x² )

Squaring both the side we get,

x² / (4 + x²) = ( x - 3)² / ( 10 -6x + x² )

⇒3x² -24x +36 =0

⇒ x² -8x + 12 = 0

⇒ x = 2 or 6 hours

Therefore , the least time taken to reach the point Q is equal to 2 hours.

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Hence, the speed that Rick must be driving on to even with Bobby at the end of the 16th lap should be: Distance = Speed × Time16=1084× Speed Speed=16×8410=134.4 mph.

The time taken by Bobby to complete 10 laps will be:

[tex]$$\begin{aligned}\text { Distance } & =\text { Speed } \times \text { Time } \\10 & =84 \times \text { Time } \\\text { Time } & =\frac{10}{84} \text { hours }\end{aligned}$$[/tex]

Hence, the speed that Rick must be driving on to even with Bobby at the end of the 16 th lap should be:

[tex]$$\begin{aligned}\text { Distance } & =\text { Speed } \times \text { Time } \\16 & =\frac{10}{84} \times \text { Speed } \\\text { Speed } & =\frac{16 \times 84}{10}=134.4 \mathrm{mph} .\end{aligned}$$[/tex]

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A quadratic equation of at the origin, estimate the error = 0.000859M

The approximation is valid because  is very small.

Calculation of  concentration:

Since

0.85 M             0           0

(0.85-x)M         x            x

Now the value of x should be

x = 0.0000229

So based on this, the above concentration should be determined.

In order to demonstrate that the same value of x may be achieved either way, you will now solve using the quadratic formula rather than iterations. What are the values of a, b, and c and x, where a, b, and c are the coefficients in the quadratic equation [tex]ax^{2} +bx+c=0[/tex] and x is [h3o+], when using the quadratic equation to determine [h3o+] in 0.00250 m hno2? Keep in mind that ka=4.5104.

a : 1

b : 4.5x[tex]10^{-4}[/tex]

c : 1.125x[tex]10^{-6}[/tex]

[[tex]H_{3} O^{+}[/tex]] = 0.000859M

As [tex]HNO_{2}[/tex] is a weak acid, its equilibrium in water is:

[tex]HNO_{2} (aq)+H_{2} O(I)[/tex] ⇄ [tex]H_{3} O^{+} (aq)+N_{2} O^{-} (aq)[/tex]

Equilibrium constant, ka, is defined as:

ka = 4.5x[tex]10^{-4}[/tex] = [[tex]H_{3} O^{+}[/tex]]  [NO₂⁻] / [HNO₂]                    (Equation-1)

Equilibrium concentration of each specie are:

[HNO₂] = 0.00250M - x

[H₃O⁺] = x

[NO₂⁻] = x

Replacing in (1):

4.5x[tex]10^{-4}[/tex] = [tex]\frac{x*x}{0.00250M-x}[/tex]

1.125x10⁻⁶ - 4.5x10⁻⁴x = x²

0 = x² + 4.5x10⁻⁴x - 1.125x10⁻⁶

As the quadratic equation is ax² + bx + c = 0

Coefficients are:

a: 1

b: 4.5x10⁻⁴

c: 1.125x10⁻⁶

Now, solving quadratic equation:

x = -0.0013 → False answer, there is no negative concentrations.

x = 0.000859

As [H₃O⁺] = x; [H₃O⁺] = 0.000859M

Therefore,

A quadratic equation of at the origin, estimate the error = 0.000859M

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The value of 'a' can be 20. The correct option is C, 20.

As per the triangle inequality theorem, the sum of any two sides of the triangle should be greater than the third side.

As per triangle inequality theorem, the sum of the two sides of the triangle should be greater than the third side of the triangle.

As per the triangle inequality theorem, if 'a' is the longest side of the triangle then,

21 + 6 > a

27 > a

If a is not the longest side of the triangle,

21 + a > 6

a > -21 + 6

a > -15

6 + a  > 21

a > 21 - 6

a > 15

Therefore, the value of a should be greater than 15 and less than 27. Since the only option under this condition is 20.

Hence, The correct option is C, 20.

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when retail cost of the computer is 37% of the wholesale price then Retail price is 1.37times wholesale price

Retailers who acquire products in bulk are subject to wholesale pricing.

Selling products at a greater price than what it costs to produce them allows businesses to turn a profit.

Retail pricing is what merchants decide to charge customers as their ultimate selling price.

Consumers are the primary focus of retail pricing.

According to the question,

The retail cost of a computer is 37% more than its wholesale cost

Let Retail cost be "x" and wholesale cost be "y"

So , x = y + 0.37y

=> x = 1.37y

Therefore , The retail price is 1.37times the wholesale price

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Answer:

  x = 15

Step-by-step explanation:

You have ∆UVW with angles U=(3x-10)°, V=(6x+5)°, and W=(4x-10)°, and you want to know the value of x.

The angle sum theorem tells you the sum of angles in a triangle is 180°.

  U +V +W = 180°

  (3x -10)° +(6x +5)° +(4x -10)° = 180°

  13x -15 = 180 . . . . . . . divide by °, collect terms

  13x = 195 . . . . . . . add 15

  x = 15 . . . . . . . divide by 13

The value of x is 15.

Answer: 75%

Step-by-step explanation:



93 is 75 percent of 124.

Explained in the picture attached...

Hope that helps...

By solving the equation we get ,t = ± 7 using concept of square roots.

How to find the square roots ?

Square root, in mathematics, a factor of a number that, when multiplied by itself, gives the original number. For example, both 3 and –3 are square roots of 9.

For example, 2 is the square root of 4, and this is expressed as √4 = 2.

We know that every squared number has two square roots one is positive and another is negative.

In given que,

given condition is t squared minus 49 = 0

Form of equation is ax^ 2 = c.

given condition can also be written as t^2 - 49 = 0

                                                          i.e. t^2 = 49

where a = 1

x = t

c = 49

So, the square root are 7 and -7.

So, equation become t = ± 7.

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Answer:

Amy has to pay $600 every month for rent.

Step-by-step explanation:

To take 1/4 of a number is to multiply 1/4 and said number.

So you can do 0.25*number

or number/4.

For this problem, the number is 2400 because Amy is going to pay 1/4 of 2400 for rent.

[tex]rent = 2400/4\\rent = 600[/tex]

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The equation of the parabola is y = -1/4 x² + 3/2 x - 17/4. Where the vertex of the equation is at (3, -2) and the focus is at (3, -2 2/16) that opens downwards.

The equation of the parabola with vertex at (h, k) is

y = a(x - h)² + k

The focus of the parabola is represented by (h, k + 1/4 a).

It is given that, the vertex of the parabola is (h, k) = (3, -2)

And the focus of the parabola is (h, k + 1/4 a) = (3, -2 1/16)

From the focus point, we can calculate the value of 'a'.

(h, k + 1/4 a) = (3, -2 1/16)

⇒ k + 1/4 a = -2 1/16 = -33/16

⇒ -2 + 1/4 a = -33/16

⇒ 1/4 a = -33/16 + 2

⇒ 1/4 a = -1/16

⇒ a = -1/16 × 4

∴ a = -1/4

Since a is negative the parabola is downwards.

Now, the equation of the parabola is

y = a(x - h)² + k

On substituting the values, we get

y = -1/4(x - 3)² - 2

  = -1/4(x² - 6x + 9) - 2

  = -1/4 x² + 3/2 x -9/4 - 2

  = -1/4 x² + 3/2 x - 17/4

Therefore, the equation of the parabola is y = -1/4 x² + 3/2 x - 17/4.

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The probabilities, using the hypergeometric distribution, are given as follows:

i) Two wear the same color: 37/105: 0.35238 = 37/105.

ii) At least 2 wear red: 0.4461.

The mass probability formula is presented as follows:

[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}C_{N-k,n-x}}{C_{N,n}}[/tex]

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

The parameters are presented as follows:

The probability of two red is given as follows:

[tex]P(X = 2) = h(2,15,2,7) = \frac{C_{7,2}C_{8,0}}{C_{15,2}} = 0.2[/tex]

The probability of two green is given as follows:

[tex]P(X = 2) = h(2,15,2,6) = \frac{C_{6,2}C_{9,0}}{C_{15,2}} = 0.14286[/tex]

The probability of two white is given as follows:

[tex]P(X = 2) = h(2,15,2,2) = \frac{C_{2,2}C_{13,0}}{C_{15,2}} = 0.00952[/tex]

Then the probability of two wearing the same color is given as follows:

0.2 + 0.14286 + 0.00952 = 0.35238 = 37/105.

The probability that out of 3 people, at least 2 wear red, is given as follows:

[tex]P(X = 2) = h(2,15,3,7) = \frac{C_{7,2}C_{8,1}}{C_{15,3}} = 0.3692[/tex]

[tex]P(X = 3) = h(3,15,3,7) = \frac{C_{7,3}C_{8,0}}{C_{15,3}} = 0.0769[/tex]

Hence:

0.3692 + 0.0769 = 0.4461.

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1405 in base 7 = 544 in base 10

What is base-7 number system ?

The heptimal system is another name for base-7 numbers. Base 7 numbers are represented by the digits 0, 1, 2, 3, 4, 5, and 6.

The digits of a Base 10 number, on the other hand, are 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. If there isn't a subscript at the supplied number, Base 10 is used to write that number. The decimal system is sometimes known as base-10 numbers. Currently, in daily life, we frequently use numbers in the base 10 range.

base 7 to  base 10 conversion:

Multiply each digits by the powers of 7 as follows:

Base 7 digits:   1         4        0         5

Multiply by:      7^3      7²      7^1      7^0

  ( 1*7^3) + (4*7² ) + (0* 7^1 )+ ( 5 *   7^0)

= 343 + 196 + 0 + 5

= 544

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The options that represent binomial random variable  are;

A. Take a random sample of 30 tours and let L = the number of tours that result in a sale.

B. Take a random sample of 3 tours and let K = the number of tours that result in a sale.

There are 4 primary conditions for a random variable to be classified as binomial random variable and they are;

1. The number of observations n is fixed.

2. Each observation is independent.

3. Each observation represents one of two outcomes ("success" or "failure").

4. The probability of "success" p is the same for each outcome.

No, in this case, since 5% of home tours result in a sale, it therefore tells us that number of home tours is the independent variable while the amount of sales generated is the dependent variable.

From the above, we can access the given options and say that the last option is not a binomial random variable because the variable M is dependent and so does not satisfy one of the four conditions.

However, options A and B satisfy the 4 conditions and we say they are binomial random variables.

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Answer:

The answer is :

E - 6c + 4t < 300

The angles after solving the equations will be equal to 50°, and both angles will be the same as the corresponding angles. Hence, option B is correct.

An angle results from the intersection of two lines at a point. The term "angle" describes the width of the "gap" that exists between these two rays. It's represented by the symbol.

Angles are most frequently measured in degrees and radians, a measurement of roundness or rotation. Angles are a part of everyday existence.

As per the given information in the question,

The equations for the angles are:

7x + 1 = 6x + 8

7x - 6x = 8 - 1

x = 7

So, the angles will be,

7x + 1 = 7(7) + 1 = 50°

6x + 8 = 6(7) + 8 = 50°

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Answer:

1000

Step-by-step explanation:

If any of the digits 0-9 can be used then there are 10^3 possible codes.

10^3 = 1000

The solution to the systems of equations is (4,1). Option C. is the answer

An algebraic equation is when two expressions are set equal to each other, and at least one variable is included

Given the: equations {(y=x²-2x+4), (y=3x):}

y= x²-2x+4 and y = 3x

substitute y = 3x into y= x²-2x+4. That is:

y= x²-2x+4

3x =  x²-2x+4

x²-2x -3x+4 = 0

x²-5x+4 = 0

By factoring:

x²-4x -1x+4 = 0

x(x-4) -1(x-4) = 0

(x-4)(x-1) = 0

x-4 = 0 or x-1 = 0

x= 4 or x = 1

Thus, the solution is (4,1)

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Answer: 72

Step-by-step explanation

Let's just look at the denominators for this problem.

8 and 18

8 can go into 24, 3 times but 18 does not multiply into 24

18 can go into 36, 2 times but 8 does not multiply into 36

Therefore 72 is the least common denominator.

8 times 9 = 72

18 times 4 = 72

72 is the least common denominator.

Simple interest at a rate of 5% per year for five years on a principle of $5,000 has resulted in a total accrual of $6,250.00, which includes both the principal and interest.

To calculate simple interest, multiply the daily interest rate by the principle and the number of days between payments. Consumers that make on-time or early monthly loan payments benefit from simple interest. Most loans with simple interest rates are auto loans and short-term personal loans.

A = $6,250.00

I = A - P = $1,250.00

Formula: A = P(1 + rt)

First, convert R percent to r decimal, which is equal to 5%/100 or 0.05 per year.

Fixing our equation

A = 5000(1 + (0.05 × 5)) = 6250 \sA = $6,250.00

Simple interest at a rate of 5% per year for five years on a principle of $5,000 has resulted in a total accrual of $6,250.00, which includes both the principal and interest.

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Answer:

Yes, there are many people who can help you with a finance question. Some of the people who can help you include: financial advisors, accountants, financial planners, and financial analysts. Additionally, there are many online resources available such as personal finance forums, websites, and blogs.

Step-by-step explanation:

The equivalent rate is 163.7 meters.

What is an equivalent rate?

Equivalent rates are different rates that have the same value. Similar to finding equivalent ratios, you may find an equivalent rate by multiplying or dividing the numerator and denominator by the same number.

Here, we have

Given: the height of one Tampa city center is 537 feet.

We have to convert 537 feet to meters by finding an equivalent rate.

1 feet = 0.3048 meter

So, 537 feet = 537 × 0.3048 = 163.7 meters.

Hence, the equivalent rate is 163.7 meters.

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Answer:

Hence, on a number line,-12 lies to the left of Zero.

Step-by-step explanation:

On a number line, zero lies exactly at the middle of the number line.Left to the zero, negative number lies and right to the zero, positive number lies.

The area of a rectangle with the sides of x+7 and 3x-4 is 3x² + 17x - 28.

Any shape's area can be calculated by counting how many unit squares will fit inside of it. A square with a side of 1 unit is referred to as a unit square in this context. Therefore, the quantity of unit squares that make up a rectangle's perimeter is its area. Alternately, the area of the rectangle is the area contained within the boundary of this shape. The unit-length tiles in your home are a good illustration of a rectangle form. By counting the number of tiles, you can quickly determine how much space the floor takes up. This will also enable you to calculate the rectangle floor's area.

Given

Sides = x+7 and 3x-4

Area of rectangle

Length ×Breadth

(x + 7) (3x - 4)

Multiplying,

x(3x - 4) + 7(3x - 4)

3x² - 4x + 21x - 28

3x² + 17x - 28

The area of a rectangle with the sides of x+7 and 3x-4 is 3x² + 17x - 28.

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The equation of the function described as;  y = 7 sin ( 4x + π/2 ) + 3

The general equation of the sine curve can be written as;

y = a sin ( nx + α ) + b

where : a is the amplitude, n = 2π/period, b = shift in the direction of y

            α°= shift in the direction of x

We are Given period = π/2 the maximum value is 10, the minimum value is −4 and y-intercept of 10.

 Thus,

a = (maximum - minimum)/2 = (10 - -4)/2

a = 7

 n = 2π/period = 2π/(π/2)

n = 4

 b = maximum - a = 10 - 7

b= 3

To find α as y-intercept = 10

y = 10 at x = 0

Substitute in the general function;

y = a sin ( nx + α ) + b

10 = 7 sin ( 4*0 + α ) + 3

Thus, we have;

sin α = 1

α = π/2

So, the equation of the function described is;

 y = 7 sin ( 4x + π/2 ) + 3

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