Answer:
b. external validity
Step-by-step explanation:
External Validity is the applicability of the results of an experiment to the real world. Most times, there are threats to the validity of an experiment which could result in little or no effect on the general population. For example, if the method of selection reflects a measure of bias, then this could affect the result. Also if the participants are taking different aspects of the same test, it could also affect its validity as they may not be able to make a correct conclusion. If the sample size is not reflective of the entire population, it could also pose a threat to the validity of the experiment.
John's experiment is weak in its external validity because it cannot be generalized to the entire population of customers. He has to identify the threats to the validity of his experiment and correct them. For example, the sample selection may be biased.
Which are steps that could be used to solve 0 = 9(x2 + 6x) – 18 by completing the square? Check all that apply. 18 + 81 = 9(x2 + 6x + 9) 18 + 9 = 9(x2 + 6x + 9) 18 + 36 = 9(x2 + 6x + 36) 11 = (x + 3)2 StartRoot 342 EndRoot = (x + 6)2 StartRoot 99 EndRoot = (x + 3)2
Answer:
18 + 81 = 9(x² + 6x + 9)
11 = (x + 3)²
When we are completing the square, we are going to move the value of c across the equals. We will do that by adding, and end up with
18=9(x²+6x)
We take the value of b (the coefficient of x), divide it by 2 and square it:
(6/2)²=3²=9
This is the value that completes the square. However, since the entire square is multiplied by 9, this value must be multiplied by 9 before we can add it across the equals:
18+9(9) = 9(x²+6x+9)
18+81=9(x²+6x+9)
99=9(x²+6x+9)
Dividing both sides by 9, we have:
11=x²+6x+9
11=(x+3)²
Answer:
18 + 81 = 9(x2 + 6x + 9) and 11 = (x + 3)2
Step-by-step explanation:
EDG
5. (03.02 MC)
If f(x) = 2х2 - 30, find f(4). (1 point)
НА
Мен
ка
ООО
Амер
-14
2
o17
Answer:
f(4) =2
Step-by-step explanation:
f(x) = 2х^2 - 30,
Let x=4
f(4) = 2 (4)^2 -30
= 2*16 -30
=32-30
= 2
What measures of the cylinder do 12 and 42 describe?
A cylinder with height of 42 millimeters and radius of 12 millimeters.
radius and diameter
radius and height
diameter and height
diameter and area of base
Answer: radius and height
Step-by-step explanation:
Radius is the distance between the center of the circle to its boundary.
Height is the length of the figure from top to bottom.
Given statement : A cylinder with height of 42 millimeters and radius of 12 millimeters.
That clearly means that the cylinder is having radius of 12 millimeters i.e. 12 is representing the measure of the radius of the cylinder.
And Similarly, 42 is representing the measure of the height of the cylinder.
Hence, the 2 and 42 describe the radius and height respectively of the cylinder.
Answer:
radius and height
Step-by-step explanation:
i just took the test edge 2020. rate me 5 stars!
Mel buys a shirt that cost 12.50 and some pairs of socks that are 2.50 each.He pays a total of 27.50$.How many pairs of socks did Mel buy?
Answer:
6
Step-by-step explanation:
Let's call the number of pairs of socks he buys s.
[tex]12.50+2.50s=27.50[/tex]
Subtract 12.50 from both sides:
[tex]2.50s=15[/tex]
Divide both sides by 2.5 to isolate s:
[tex]s=6[/tex]
Hope this helps!
6x +7y=-46 3x-2y=32 solve this system of linear equations
Hello
We have two equations and need to find x and y
(1) 6x+7y=-46
(2) 3x-2y=32
multiply (2) by 2 it gives
(2') 6x-4y=64
(1) - (2') gives
6x+7y-6x+4y=-46-64 = -110
so 11y = -110
y = -10
replace in (2) it gives
3x+20=32
3x=12
x = 12/3 = 4
the solution is (4,-10)
do not hesitate if you need further explanation
if you like my answer, tag it as the brainliest :-)
Use z scores to compare the given values. Based on sample data, newborn males have weights with a mean of 3259.6 g and a standard deviation of 722.4 g. Newborn females have weights with a mean of 3031.2 g and a standard deviation of 495.9 g. Who has the weight that is more extreme relative to the group from which they came: a male who weighs 1700 g or a female who weighs 1700 g? Since the z score for the male is zequals nothing and the z score for the female is zequals nothing, the female female male has the weight that is more extreme.
Answer:
Since the z score for the male is z=-2.1589 and the z score for the female is z=-2.6844, the female has the weight that is more extreme.
Step-by-step explanation:
To find the z score, we use the following equation:
[tex]z=\frac{x-m}{s}[/tex]
Where m is the mean and s is the standard deviation.
So, the z score for a male who weighs 1700 g is:
[tex]z=\frac{1700-3259.6}{722.4}=-2.1589[/tex]
At the same way, the z score for a female who weighs 1700 g is:
[tex]z=\frac{1700-3031.2}{495.9}=-2.6844[/tex]
Finally, -2.6844 is farther from zero than -2.1589, so the female has the weight that is more extreme.
12
? Select three options.
Which phrases can be represented by the algebraic expression
W
12 divided by a number
the quotient of 12 and a number
a number divided by 12
a number divided into 12
the product of 12 and a number
Answer:
Step-by-step explanation: its 24
1,2,5
Step-by-step explanation:
Determine the interest earned on a 3 and 1/4 year investment of $2880 at a rate of 4.5%
Answer:
The interest earned is $421.2.
Step-by-step explanation:
This is a simple interest problem.
The simple interest formula is given by:
[tex]E = P*I*t[/tex]
In which E is the amount of interest earned, P is the principal(the initial amount of money), I is the interest rate(yearly, as a decimal) and t is the time.
In this question:
[tex]P = 2880, I = 0.045, t = 3 + \frac{1}{4} = 3.25[/tex]
So
[tex]E = P*I*t[/tex]
[tex]E = 2880*0.045*3.25[/tex]
[tex]E = 421.2[/tex]
The interest earned is $421.2.
Find the value of z
Answer:
87°
Step-by-step explanation:
In the given figure, a quadrilateral is inscribed in a circle. Therefore, it is a cyclic quadrilateral.
Opposite angles of a cyclic quadrilateral are supplementary.
[tex] \therefore \: z + 93 \degree = 180 \degree \\ \therefore \: z = 180 \degree - 93 \degree \\ \huge \red{ \boxed{\therefore \: z = 87 \degree}}[/tex]
Assume that the probability of a driver getting into an accident is 7.1%, the
average cost of an accident is $14,886.05, and the overhead cost for an
insurance company per insured driver is $110. What should the driver's
insurance premium be?
O A. $1276.27
O B. $1242.93
O C. $1165.49
O D. $1156.43
Answer:
C - $1165.49
Step-by-step explanation:
We have that the probability of a driver getting into an accident = 7.1% i.e. 0.071.
Now, the average cost of an accident = $14,886.05
Then, the expected cost of an accident = $14,886.05 × 0.071 = $1056.91
As, the overhead cost for insurance = $110
Therefore, the driver's insurance premium = $1056.91 + $110 = $1166.91
Since, the closest option to $1166.91 is option C.
Hence, the driver's insurance premium will be $1165.49.
the driver's insurance premium will then be,
⇒ $1166.91
What is mean by Percentage?
A number or ratio that can be expressed as a fraction of 100 or a relative value indicating hundredth part of any quantity is called percentage.
To Calculate the percent of a number , divide the number by whole number and multiply by 100.
Now, The following can be deduced from the question:
Average cost of an accident = $14,886.05
Probability of a driver getting into an accident = 7.1%
= 7.1/100
= 0.071.
Overhead cost for insurance = $110
Therefore, the expected cost of an accident will be calculated as:
= Average cost of an accident × Probability of a driver getting into an accident
= $14,886.05 × 0.071
= $1056.91
Therefore, the driver's insurance premium will then be:
= $1056.91 + $110
= $1166.91
Learn more about the percent visit:
https://brainly.com/question/24877689
#SPJ5
If Romeo earns 8% more than Juliet, Romeo’s salary is how many times Juliets salary?
A) 1.08
B) 0.92
C) 80
D) 108
Answer:
1.08
Step-by-step explanation:
If Romeo earns 8% more than Juliet,
Example?
If Juliet earns $80
80x8% = 6.40 So his pay would be 80 + 6.40
If you times 80 by 1.08 (this would also be 108%) you would get $86.40
Which is equivalent to 8−+3
8
x
-
y
+
3
x
?
Answer:
DIDNT UNDERSTAND THE QUESTION PROPERLY BRO..
KEEP THE QUESTION AGAIN
Write an expression for "the quotient of z and 4
Answer:
z/4
Step-by-step explanation:
you divide the numerator by the denominator
Answer:
z/4 is the answer
please brainliest me
Step-by-step explanation:
and can me divide which is also (/)
Solve the inequality for y.
-4y ≤ -12
Divide both sides by -4:
y ≤ 3
Because both sides were divided by a negative value you need to reverse the inequality sign:
y ≥ 3
Answer:
y = 3
Step-by-step explanation:
it says -4y ≤ -12 sooooooo 4 x 3 = 12!!!! so y = 3
Quinn used a scale drawing to build a soccer field near his school. Initially, he wanted the field to be 28 yards long and 17.5 yards wide. He decided to change the length of the field to 36 yards.
If the width is to be changed by the same scale factor, what is the new width of the field? Express your answer to the nearest tenth.
18.5
22.5
25.5
57.6
Answer:
So the answer is going to be B. AKA 22.5
Step-by-step explanation:
I took the test on ed and got this answer right! hth (hope this helps)
Answer:
B, second option, 22.5
Step-by-step explanation:
1.)because
2.)i'm
3.)kinda
4.)smart
answer=22.5:))))))))
Avantraveling 20 miles per hour can stop in 60 feet. If a van is traveling 32 miles per hour what is it’s stopping distance
Find the 1000th term for the sequence
Answer:
D. 7017
Step-by-step explanation:
if 24 is the first term, find 7x999, or 7x1000-7 and add 24
however a better way would be to use the formula
value=a+(n-1)d
a = the first term in the sequence (24)
n = the amount of terms you need (1000)
d = the common difference between terms (7)
60 is what percent of 400
Answer:
15%
Step-by-step explanation:
Is means equals and of means multiply
60 = P * 400
Divide each side by 400
60/400 = P
.15 = P
Change to percent form
15% is the percent
Answer:
the answer to the question you've asked is 15
A 120-gallons (gal)tank initially contains 90 lb of a salt dissolved in 90 gal of water. Brine containing 2 lb/gal of salt flows into the tank at the rate of 4gal/min. The mixture is kept uniform by stirring, and the stirred mixture flows out at the rate of 3gal/min. How much salt does the tank contain when it is full
Answer:
The tank will contain 202 Ib of salt when it's full.
Step-by-step explanation
To find the amount of salt in the tank at time t= x(t)
If x(0)= 90Ib
To find the volume of the tank at time t
V(t)= 90+(4-3)t=90+t gal
Other solutions are found attached
can someone help me please? its urgent
Answer:
Step-by-step explanation:
Answer:
972^1/4 = 4 ⁴√3
448^1/3 = 4 ³√7
3528^1/2 = 42√2
4050^1/4 = 3 ⁴√50
Hope this helps.
Which value of a in the exponential function below would cause the function to shrink? f(x) = a(three-halves) Superscript x Four-fifths Five-fourths Three-halves Seven-fourths
Answer:
Four-fifths
Step-by-step explanation:
As we know that
By multiplying the function by a constant, we may expand or shrink the function in the y-direction.
Now we have
[tex]y=a(b^{x})[/tex]
if [tex]a> 1[/tex] > the function would enlarge
if [tex]0< a < 1[/tex] > the function would shrinks
Now
For case A
[tex]a = \frac{4}{5}[/tex]
[tex]0 < (\frac{4}{5} )< 1[/tex] ....... > the function would shrinks
For case B
[tex]a = \frac{5}{4}[/tex]
[tex](\frac{5}{4} )>1[/tex] .......> the function would enlarge
For case C
[tex]a = \frac{3}{2}[/tex]
[tex](\frac{3}{2} )>1[/tex] .........> the function would enlarge
For case D
[tex]a = \frac{7}{4}[/tex]
[tex](\frac{7}{4} )>1[/tex] .........> the function would enlarge
Therefore the second option is correct
Answer: 4/5
Step-by-step explanation: E2020
What is the area & perimeter of this figure?
Answer:
The perimeter is
Step-by-step explanation:
perimeter is the whole distance you will go around the shape
Perimeter= 19 +3+(19-5)+(8-3)+5+8
= 19+3+14+5+5+8
= 54
For area, cut the triangle into small and big rectangle
Area = 19 * 3+ (8-3) * 5
= 57 + 25
= 82
Length of a rod: Engineers on the Bay Bridge are measuring tower rods to find out if any rods have been corroded from salt water. There are rods on the east and west sides of the bridge span. One engineer plans to measure the length of an eastern rod 25 times and then calculate the average of the 25 measurements to estimate the true length of the eastern rod. A different engineer plans to measure the length of a western rod 20 times and then calculate the average of the 20 measurements to estimate the true length of the western rod.
Answer:
b. The engineer who weighed the rod 25 times.
Step-by-step explanation:
Hello!
Full text:
Length of a rod: Engineers on the Bay Bridge are measuring tower rods to find out if any rods have been corroded from salt water. There are rods on the east and west sides of the bridge span. One engineer plans to measure the length of an eastern rod 25 times and then calculate the average of the 25 measurements to estimate the true length of the eastern rod. A different engineer plans to measure the length of a western rod 20 times and then calculate the average of the 20 measurements to estimate the true length of the western rod.
Suppose the engineers construct a 90% confidence interval for the true length of their rods. Whose interval do you expect to be more precise (narrower)?
a. Both confidence intervals would be equally precise.
b. The engineer who weighed the rod 25 times.
c. The engineer who weighed the rod 20 times.
X₁: Length of an eastern rod of the Bay Bridge
n₁= 25
X₂: Length of a western rod of the Bay Bridge
n₂= 20
Both Engineers will use their samples to estimate the population average length of the rods using a 90% CI.
Assuming the standard normal distribution, the confidence interval will be centered in the estimated mean.
X[bar] ± [tex]Z_{1-\alpha /2}[/tex]*(σ/√n)
And the width is determined by the semi amplitude:
↓d= [tex]Z_{1-\alpha /2}[/tex]*(σ/√↑n)
As you can see the sample size has an indirect relationship with the semi amplitude of the interval. This means, when the sample size increases, the semi amplitude decreases, and if the sample size decreases, the semi amplitude increases. Naturally this is leaving all other elements of the equation constant, this means, using the same confidence level and the same population standard deviation.
Since the first engineer took the larger sample, he's confidence interval will be narrower and more accurate.
Hope this helps!
Which expression is equivalent to log Subscript 8 Baseline 4 a (StartFraction b minus 4 Over c Superscript 4 Baseline EndFraction)?
Answer:
[tex]\log_84+\log_8a+\log_8(b-4)-4\log_8c[/tex].
Step-by-step explanation:
The given expression is
[tex]\log_84a\left(\dfrac{b-4}{c^4}\right)[/tex]
Using the properties of logarithm, we get
[tex]\log_84+\log_8a+\log_8\left(\dfrac{b-4}{c^4}\right)[/tex] [tex][\because \log_a mn=\log_a m+\log_a n][/tex]
[tex]\log_84+\log_8a+\log_8(b-4)-\log_8c^4[/tex] [tex][\because \log_a \frac{m}{n}=\log_a m-\log_a n][/tex]
[tex]\log_84+\log_8a+\log_8(b-4)-4\log_8c[/tex] [tex][\because \log_a x^n =n\log_a x][/tex]
Therefore, the required expression is [tex]\log_84+\log_8a+\log_8(b-4)-4\log_8c[/tex].
Answer:
B on edge
Step-by-step explanation:
Help me please the questions are in the picture!!! THX MARK U AS BRAINIEST
Answer:
D is 10
b/12
Step-by-step explanation:
YOU KNOW THE DRILL 2.0
Answer:
#1
Step-by-step explanation:
The four yellow boxes represent x so together they are 4 * x or 4x. The blue boxes seem to represent -1 and since there are three of them together they are -1 * 3 = -3. 4x + (-3) = 4x - 3.
What is the approximate value of sin B?
B
>
17.46
7
A
16
Answer:
Option (B)
Step-by-step explanation:
From the figure attached,
AB = 7 units
BC = 17.46 units
AC = 16 units
Now we apply the sine rule in the given triangle ABC,
SinB = [tex]\frac{\text{Opposite side}}{\text{Hypotenuse}}[/tex]
= [tex]\frac{AC}{BC}[/tex]
= [tex]\frac{16}{17.46}[/tex]
= 0.916
≈ 0.92
Therefore, Option (B) will be the answer.
Answer:
DIFFERENT PICS
Step-by-step explanation:
I had one and the awnser was 0.40, and C had a arch whereas B did not.
Please help me. I’ll mark you as brainliest if correct
Answer:
b = -18
Step-by-step explanation:
(3 + 4i) (-3-2i)
When we foil:
-9 + -6i + -12i + -8i^2
-8i^2 = +8
Combine like terms:
-1 + -18i
URGERNT!!!PLS AT LEAST TAKE A LOOK!!! SHARE YO SMARTNESSS!! AND BLESS YOUR GRADES!
Which sign explains the relationship between m∠1 and m∠2 in the diagram?
A) not equal to
B) >
C) <
D) =
Answer:
Dear Laura Ramirez
Answer to your query is provided below
Option D is correct.
Reason - Because of Hinge and Converse of Hinge theorem
Anyone know how to solve this
Answer:
Y=1800+150x
Step-by-step explanation:
Answer:
4. Y = 150x + 1800