What's the answer and the work

alina1380 [7]

X is 4 because 64 is 8 squared, so 4 would be 2 squared

4 0

2 years ago

Listed below are the measured radiation emissions (in W/kg) corresponding to cell phones: A, B, C, D, E, F, G, H, I, J, a

Sophie [7]

Answer: a. Mean = 0.696364

b. Median = 0.64

c. Midrange = 0.895

d. There is no Mode

e. 2. The maximun data value is the most relevant statistic, because it is closest to the limit of 1.6W/kg and that cell should be avoided.

Step-by-step explanation:

a) Mean is an average number of the data set, calculated by the sum of all the value divided by the quantity of the set:

mean = $\frac{0.75+0.22+1.23+0.64+0.54+0.24+0.81+1.57+0.29+1.02+0.35}{11}$

mean = 0.696364

b) Median is the middle number in the list of numbers. In this case, since there are 11 elements in the set, the middle number is:

sorted numbers of the data set:

0.22 0.24 0.29 0.35 0.54 0.64 0.75 0.81 1.02 1.23 1.57

median = 0.64

c) Midrange is another type of average number. It is calculated as:

midrange = $\frac{high+low}{2}$

midrange = $\frac{1.57+0.22}{2}$

midrange = 0.895

d) Mode is the number that appears most often in the list of numbers. For this data set, each number appears only one time, so there is no mode.

Mode = 0

e) According to the question, cell phone radiation is dangerous when it is higher than 1.6W/kg. The cell phone with the maximum data value (1.57 W/kg) should be avoided, since it is too close to the limit described.

So, the measures of center are not the most important statistic to be observed but the maximum data value.

7 0

2 years ago

If an object is shot with an initial velocity of 160 ft/sec, what is the smallest initial angle will you need to obtain a horizo

MrRissso [65]

To solve the question we shall use the formula for the range given by:
Horizontal range, R=[v²sin 2θ]/g
plugging in our values we get:
500=[160²×sin 2θ]/10
5000=160²×sin 2θ
0.1953=sin 2θ
thus:
arcsin 0.1953=2θ
11.263=2θ
hence:
θ=5.6315°~5.63

3 0

3 years ago

Jermaine, Keira, and Leon are buying supplies for an art class. Jermaine bought 2 canvases, 4 tubes of paint, and 2 paint brushe

maria [59]

Answer:

canvas $3

tube of paint $5

paint brush $4

Step-by-step explanation:

We need to choose variables for the prices of the different items, translate the sentences into equations, and solve a system of equations.

1. Define variables

Let c = price of 1 canvas, t = price of 1 tube of paint, and b = price of 1 brush.

2. Translate sentences into equations

"Jermaine bought 2 canvases, 4 tubes of paint, and 2 paint brushes for $34."

2c + 4t + 2b = 34

"Keira spent $22 on 1 canvas, 3 tubes of paint, and 1 paint brush."

c + 3t + b = 22

"Leon already has plenty of paint, so he bought 3 canvases and 2 paint brushes for $17."

3c + 2b = 17

The system of equations is

2c + 4t + 2b = 34 Eq. 1

c + 3t + b = 22 Eq. 2

3c + 2b = 17 Eq. 3

Since the third equation has only the variables c and b, we use the first equations to eliminate variable t and give us an equation in only c and b.

3 * Eq. 1 - 4 * Eq. 2

2c + 2b = 14

c + b = 7 Eq. 4

Eq. 3 and Eq. 4 form a system of equations in two variables.

3c + 2b = 17 Eq. 3

c + b = 7 Eq. 4

Solve Eq. 4 for b.

b = 7 - c Eq. 5

Substitute into Eq. 3.

3c + 2(7 - c) = 17

3c + 14 - 2c = 17

c = 3

Plug in c = 3 into Eq. 5.

b = 7 - 3

b = 4

Plug in c = 3 and b = 3 into Eq. 2.

c + 3t + b = 22 Eq. 2

3 + 3t + 4 = 22

3t + 7 = 22

3t = 15

t = 5

Answer:

canvas $3

tube of paint $5

paint brush $4

7 0

2 years ago

A: What are the solutions to the quadratic equation x2+9=0? B: What is the factored form of the quadratic expression x2+9? Selec

Paraphin [41]

Answer:

A. The solutions are $x=3i,\:x=-3i$ .

B. The factored form of the quadratic expression $x^2+9=(x-3i)(x+3i)$

Step-by-step explanation:

A. To find the solutions to the quadratic equation $x^2+9=0$ you must:

$\mathrm{Subtract\:}9\mathrm{\:from\:both\:sides}\\\\x^2+9-9=0-9\\\\\mathrm{Simplify}\\\\x^2=-9\\\\\mathrm{For\:}x^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}x=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}\\\\x=\sqrt{-9},\:x=-\sqrt{-9}$

$x=\sqrt{-9} = \sqrt{-1}\sqrt{9}=\sqrt{9}i=3i\\\\x=-\sqrt{-9}=-\sqrt{-1}\sqrt{9}=-\sqrt{9}i=-3i$

The solutions are:

$x=3i,\:x=-3i$

B. Two expressions are equivalent to each other if they represent the same value no matter which values we choose for the variables.

To factor $x^2+9$ :

First, multiply the constant in the polynomial by $i^2$ where $i^2$ is equal to -1.

$x^2+9i^2$

Since both terms are perfect squares, factor using the difference of squares formula

$a^2-i^2=(a+i)(a-i)$

$x^2+9=x^2+9i^2=\left(-3i+x\right)\left(3i+x\right)$

5 0

2 years ago