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4 years ago

A student timed his drive to work each day for three days. The times are shown below:

Mathematics

2 answers:

cupoosta [38]4 years ago

8 0

Answer:

20 minutes

Step-by-step explanation:

The mean, or average of a data set can be found by adding all the values together, and dividing by the number of values.

The data set is: 20 minutes, 22 minutes and 18 minutes

1. Add the values together

Add all the numbers in the set together.

Data set: 20, 22, 18

Add them: 20+22+18

2. Divide by the number of values

Count how many numbers are in the set.

In this set, there are 3 numbers.

Divide 60 by 3

60/3 =20

20 minutes

His mean time is 20 minutes.

ella [17]4 years ago

3 0

Answer:

30 minutes

Step-by-step explanation:

Mean means the average so the average equals (20+22+18)/2

= 30

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Common factor the GCF of 27y^2 and 36^3

ollegr [7]

9 because it is the highest number that it can go it both 27 and 36

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3 years ago

Find all points on the x-axis that are 14 units from the point (4, -7).

BaLLatris [955]

Answer:

The points are: (16.12,0),(-8.12,0).

Step-by-step explanation:

Solving a quadratic equation:

Given a second order polynomial expressed by the following equation:

$ax^{2} + bx + c, a\neq0$ .

This polynomial has roots $x_{1}, x_{2}$ such that $ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})$ , given by the following formulas:

$x_{1} = \frac{-b + \sqrt{\bigtriangleup}}{2*a}$

$x_{2} = \frac{-b - \sqrt{\bigtriangleup}}{2*a}$

$\bigtriangleup = b^{2} - 4ac$

Distance between two points:

Suppose we have two points, $(x_1,y_1)$ and $(x_2,y_2)$ . The distance between them is given by:

$D = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$

Find all points on the x-axis that are 14 units from the point (4, -7).

Being on the x-axis mean that they have y-coordinate equal to 0, so the point is (x,0).

The distance is 14. So

$\sqrt{(x-4)^2+(0-(-7))^2} = 14$

$\sqrt{x^2 - 8x + 16 + 49} = 14$

$\sqrt{x^2 - 8x + 65} = 14$

$(\sqrt{x^2 - 8x + 65})^2 = 14^2$

$x^2 - 8x + 65 - 196 = 0$

$x^2 - 8x - 131 = 0$

So $a = 1, b = -8, c = -131$

$\bigtriangleup = (-8)^{2} - 4(1)(-131) = 588$

$x_{1} = \frac{-(-8) + \sqrt{588}}{2} = 16.12$

$x_{1} = \frac{-(-8) - \sqrt{588}}{2} = -8.12$

The points are: (16.12,0),(-8.12,0).

4 0

3 years ago

A certain three-cylinder combination lock has 60 numbers on it. To open it, you turn to a number on the first cylinder, then

statuscvo [17]

Answer:

(a) The number of different lock combinations is 216,000.

(b) The probability of getting the correct combination in the first try is $\frac{1}{216000}$ .

Step-by-step explanation:

The lock has three-cylinder combinations with 60 numbers on each cylinder.

The procedure of the opening lock is to turn to a number on the first cylinder, then to a second number on the second cylinder, and then to a third number on the third cylinder.

The numbers can be repeated.

(a)

There are three cylinder combinations on the lock, each with 60 numbers.

It is provided that repetitions are allowed.

Then each cylinder can take any of the 60 numbers.

So there are 60 options for the first cylinder.

There are 60 options for the second cylinder.

And there are 60 options for the third cylinder.

So the total number of possible combinations is:

Total number of combinations = 60 × 60 × 60 = 216000.

Thus, the number of different lock combinations is 216,000.

(b)

The events of getting a correct combinations of the three-cylinder combination lock implies that all the three cylinder are set at the correct numbers.

Each cylinder has 60 numbers.

This implies that there are 60 possible ways to get a correct number for the first cylinder.

The probability of getting the correct number for the first cylinder is:

P (Number on 1st cylinder is correct) = $\frac{1}{60}$ .

Similarly for the second cylinder the probability of getting the correct number is:

P (Number on 2nd cylinder is correct) = $\frac{1}{60}$ .

And similarly for the third cylinder the probability of getting the correct number is:

P (Number on 3rd cylinder is correct) = $\frac{1}{60}$ .

So the probability of getting the correct combination in the first try is:

P (Correct combination in the 1st try) = $\frac{1}{60}\times \frac{1}{60}\times \frac{1}{60}=\frac{1}{216000}$ .

Thus, the probability of getting the correct combination in the first try is $\frac{1}{216000}$ .

7 0

3 years ago

Each side of a square is increasing at a rate of 6cm/s. At what rate is the area of the square increasing when the area of the s

diamong [38]

Area of a square = length²
A = x²
16 = x²; x = 4
dA/dx = 2x cm²/s
dx/dt = 6 cm/s
Using chain rule:
dA/dt = dA/dx * dx/dt
dA/dt = 2x * 6
dA/dt = 12x
At x = 4,
dA/dt = 12(4) = 48 cm²/s

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4 years ago

-2.05 is greater or less than -2.50

Xelga [282]

Answer:

less than is the answer

3 0

4 years ago

Read 2 more answers