Ask question

Ask question

All categories

3 years ago

8

In an experimental design, the variable over which the researcher has no control but that is measured to find the effect of the

treatment is called the _____.

2 answers:

Lesechka [4]3 years ago

8 0

Answer: explanatory?

Step-by-step explanation:

Tema [17]3 years ago

6 0

Answer: C) Response variable

The independent variable (the one the researcher has control over) is the explanatory variable.

You might be interested in

Find the distance between the points (7,-6) and (-5,3). Write your answers as a whole number or a fully simplified radical expre

nexus9112 [7]

Answer:

15

Step-by-step explanation:

Let index 1 refer to the first point, while index 2 refers to the second one.

The distance d:

d²=(x2-x1)²+(y2-y1)²=(-5-7)³+(3-(-6))²=

(-12)²+9²=144+81=225=15²

d=15

3 0

3 years ago

Bt= 8500 *(8/27)^t/3After a special medicine is introduced into a Petri dish full of bacteria, the number of bacteria remaining

ozzi

Answer:

Every 1.71 seconds, the bacteria loses $\frac{1}{2}$

Step-by-step explanation:

Given

$B(t) = 8500 * (\frac{8}{27})^\frac{t}{3}\\$

Required [Missing from the question]

Every __ seconds, the bacteria loses $\frac{1}{2}$

First, we model the function from t/3 to t.

$B(t) = 8500 * (\frac{8}{27})^\frac{t}{3}\\$

Apply law of indices

$B(t) = 8500 * (\frac{8^\frac{1}{3}}{27^\frac{1}{3}})^t$

Evaluate each exponent

$B(t) = 8500 * (\frac{2}{3})^t$ --- This gives the number of bacteria at time t

At time 0, we have:

$B(0) = 8500 * (\frac{2}{3})^0$

$B(0) = 8500 * 1$

$B(0) = 8500$

Let r be the time 1/2 disappears.

When 1/2 disappears, we have:

$B(r) = \frac{B(0)}{2}$

$B(r) = \frac{8500}{2}$

$B(r) = 4250$

So, we have:

$B(t) = 8500 * (\frac{2}{3})^t$

Substitute r for t

$B(r) = 8500 * (\frac{2}{3})^r$

Substitute $B(r) = 4250$

$4250 = 8500 * (\frac{2}{3})^r$

Divide both sides by 8500

$\frac{4250}{8500} = (\frac{2}{3})^r$

$\frac{1}{2} = (\frac{2}{3})^r$

Take log of both sides

$log(\frac{1}{2}) = log (\frac{2}{3})^r$

Apply law of logarithm

$log(\frac{1}{2}) = r\ log (\frac{2}{3})$

Make r the subject

$r = log(\frac{1}{2}) / log (\frac{2}{3})$

$r = \frac{-0.3010}{-0.1761}$

$r = 1.71$

<em>Hence, it reduces by 1/2 after every 1.71 seconds</em>

6 0

3 years ago

What is the value of x

goblinko [34]

Answer:

52/3

Step-by-step explanation:

Use basic Thales therom,

$\frac{3x}{4x}=\frac{3x+7}{5x-8}\\\\\frac{3}{4}=\frac{3x+7}{5x-8}\\$

Cross multiply,

3*(5x-8)=4*(3x+7)

3*5x - 3*8 = 4*3x + 4*7

15x - 24 = 12x +28

Add 24 to both sides

15x = 12x + 28 + 24

15x = 12x + 52

Subtract 12x from both sides

15x-12x =52

3x = 52

Divide both sides by 3

x = 52/3

8 0

3 years ago

Identify the correct statement for the given figure.

neonofarm [45]

Answer:

B

Step-by-step explanation:

b/c the figure is right angle

4 0

3 years ago

Read 2 more answers

(2x^2+3x-8)+(3x^2+9x+17)-(5x^2-15)

Lelechka [254]

Answer:

12(x+2)

Step-by-step explanation:

(2x^2+3x-8)+(3x^2+9x+17)-(5x^2-15)

6 0

4 years ago