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3 years ago

How can you use 1300 divided by 13 to help you find 1,287 divided 13

Mathematics

1 answer:

tiny-mole [99]3 years ago

6 0

Answer:

Step-by-step explanation:

This question is about the benefits of estimation.

1300/13 is easy and results in 100.

1287/13 can be approximated by 1300/13: 1287/13 ≈ 100.

Actually, 1287 = 1300 - 13 = 13(99); just subtract 1 from 100.

So: 1287/13 = 1300 - 13 = 1287. A nice bit of mental math!

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1. Each month, the city of Accra generates an average of 28 pounds of waste. Assume the variable is approximately normally distr

Molodets [167]

1. Answer: given: an average of 28 pounds

Find z values corresponding to 27 and 31:

z=%2827-28%29%2F2=-1%2F2=-0.5

z=%2831-28%29%2F2=3%2F2=1.5

Find the area between z+=+-0.5 and z=+1.5

Table E gives us an area of 0.9332-0.30=0.6247=> The probability is 62.47%

Find z values corresponding to 30.2

z=%2830.2-28%29%2F2=2.2%2F2=1.1 Find the area to the right of z+=1.1

it gives you an area of 0.1357=> The probability is 13.57%

7 0

3 years ago

What is the value of x?

V125BC [204]

The value of X is 1

7 0

3 years ago

A plane flying horizontally at an altitude of 1 mi and a speed of 470 mi/h passes directly over a radar station. Find the rate a

kiruha [24]

Answer:

407 mi/h

Step-by-step explanation:

Given:

Speed of plane (s) = 470 mi/h

Height of plane above radar station (h) = 1 mi

Let the distance of plane from station be 'D' at any time 't' and let 'x' be the horizontal distance traveled in time 't' by the plane.

Consider a right angled triangle representing the above scenario.

We can see that, the height 'h' remains fixed as the plane is flying horizontally.

Speed of the plane is nothing but the rate of change of horizontal distance of plane. So, $s=\frac{dx}{dt}=470\ mi/h$

Now, applying Pythagoras theorem to the triangle, we have:

$D^2=h^2+x^2\\\\D^2=1+x^2$

Differentiating with respect to time 't', we get:

$2D\frac{dD}{dt}=0+2x\frac{dx}{dt}\\\\\frac{dD}{dt}=\frac{x}{D}(s)$

Now, when the plane is 2 miles away from radar station, then D = 2 mi

Also, the horizontal distance traveled can be calculated using the value of 'D' in equation (1). This gives,

$2^2=1+x^2\\\\x^2=4-1\\\\x=\sqrt3=1.732\ mi$

Now, plug in all the given values and solve for $\frac{dD}{dt}$ . This gives,

$\frac{dD}{dt}=\frac{1.732\times 470}{2}=407.02\approx 407\ mi/h$

Therefore, the distance from the plane to the station is increasing at a rate of 407 mi/h.

6 0

3 years ago

Find the equation of the line through (-9,6) that is perpendicular to the line through (7,8),

Setler [38]

Step-by-step explanation:

I assume as "equation" we mean the slope-intercept form :

y = ax + b

"a" is the slope of the line (y coordinate change / x coordinate change when going from one point to another on the line). b is the y-intercept (the y value when x = 0).

we get the slope by finding the perpendicular slope of the first line.

the slope of the first line when going from (-3, -9) to (7, 8) :

x changes by + 10 (from -3 to +7).

y changes by + 17 (from -9 to +8).

so, that slope is 17/10.

the perpendicular slope is turning the original slope upside-down and flips the sign :

-10/17

so, a = -10/17

now, as we have only the slope and a point of the new line, we can use the point-slope form to stay and then transfer into the slope-intercept form.

y - y1 = a(x - x1)

where "a" is again the slope, and (x1, y1) is a point on the line

y - -6 = -10/17 × (x - -9)

y + 6 = -10/17 × (x + 9) = -10/17 × x - 90/17

y = -10/17 × x - 90/17 - 6 =

= -10/17 × x - 90/17 - 102/17 =

= -10/17 × x - 192/17

so, the equation is (in a maybe nicer way)

y = -1/17 × (10x + 192)

7 0

1 year ago

Question 1 (Essay Worth 10 points)

zysi [14]

$394.51 is future value of money after 2 years.

What future value means?

A current asset's future value (FV), which is based on an estimated rate of growth, is its value at a later time.
Investors and financial planners use the future value to project how much an investment made now will be worth in the future.

The method that results in more money after 2 years is Peggy's investment.

Which method results in more money in 2 years?

The formula for calculating the future value of an investment:

FV = P (1 + r)^nm

FV = Future value

P = Present value

R = interest rate

m = number of compounding

N = number of years

Future value of Larry's investment: $350 x [1 + (0.04/4)]^(4 x 2) = $379

Future value of Peggy's investment: $350 x [1 + (0.06/12)]^(12 x 2) = $394.51

Learn more about future value

brainly.com/question/14860893

#SPJ13

4 0

1 year ago