Explain why a sample of 30 dentists from a large city taken to estimate the median income of all residents of that large city is not representative
Answer: Because all individuals in the sample have the same job, so the sample is biased.
Step-by-step explanation:
Ignoring the fact that 30 is a small sample for a large city, we already know that all the people in the sample has the same profession.
Now, we can expect that two dentists win have around the same income, but not all the residents in the city are dentists
A lot of them work in fast food, others may be lawyers, others may be freelancers.
We have a lot of jobs where the income does not coincide with the average income of a dentist, so with the sample of 30 dentists we are not actually representing all the other possible jobs that there are in the city.
If we want a sample that represents the income of all the residents, we should have a random sample (so the sample is not biased, like in this case).
Dos motos, A y B, toman la salida en una carrera de 90 km. La moto A realiza el recorrido con una velocidad media inferior en 20 km/h a la de la moto B, con lo que llega a la meta 3 minutos después que B. Calcula la velocidad de cada moto.
Answer:
motorcycle A: 180 km/h
motorcycle B: 200 km/h
Step-by-step explanation:
To solve this question we need to write a system of equations for A and B, using the equation:
distance = speed * time
The speed of A is 20 less than the speed of B, so:
speedA = speedB - 20
And the time A traveled is 3 minutes (0.05 hours) more than B's time, so:
timeA = timeB + 0.05
Then, using the distance equation, we have that:
distanceB = speedB * timeB
90 = speedB * timeB
distanceA = speedA * timeA
90 = (speedB - 20) * (timeB + 0.05)
90 = speedB * timeB + 0.05 * speedB - 20*timeB - 1
90 = 90 + 0.05 * speedB - 20*timeB - 1
20*timeB = 0.05 * speedB - 1
timeB = (speedB - 20)/400
using this timeB in the distance equation, we have:
90 = speedB * (speedB - 20)/400
90 * 400 = speedB^2 - 20*speedB
speedB^2 - 20*speedB - 36000 = 0
Solving this quadratic equation, we have speedB = 200 km/h
And the speedA is:
speedA = speedB - 20 = 200 - 20 = 180 km/h
How many square roots is the area ?
Can someone please help with this question.
Answer:
54cm³
Step-by-step explanation:
V=0.5*b*h
b = 3*9 = 27cm²
h=4cm
V=0.5*4*27=54cm³
The cost of a service call to fix a washing machine can be expressed by the linear function Y = 45x+35, where y represents th
total cost and x represents the number of hours it takes to fix the machine. What does the y-intercept represent?
Answer: brainliesss plsss
The cost of a service call to fix a washing machine can be expressed
Step-by-step explanation:
The cost of a service call to fix a washing machine can be expressed by the linear function y=45x+35 where y represents the total cost and x represents the number of hours it takes to fix the machine.
Answer:
whats the real answer?
Step-by-step explanation:
A number is decreased by seven. Then, the new number is multiplied by 3 to get an answer of -9. What is the original number? ( please hurry i need to finish my assesment )
A.) - 4
B.) - 30
C.) 4
D.) 30
Answer: -4
Step-by-step explanation:reverse the steps
3(x-7)= -9
3(x-7)/3= -9/3
x-7= -3
x= -3+7
x= -4
a Fair coin is tossed 3 times. What is the probability of getting at least one heads and at least one tails?
Answer:
b. 75%
Step-by-step explanation:
Here are all the outcomes of three coin tosses:
HHH
HHT
HTH
HTT
THH
THT
TTH
TTT
There are a total of 8 possible outcomes.
1 outcome is all heads.
1 outcome is all tails.
6 outcomes have at least one heads and 1 tails
p(at least 1 heads and at least 1 tails) = 6/8 = 3/4 = 75%
I will give you brainliest!!!! Add the equations.
Answer:
7x = 9
Step-by-step explanation:
3x -2y = 15
4x+2y = -6
---------------------
7x + 0y = 9
7x = 9
Anyone mind helping out with my math?
Answer:
no
Step-by-step explanation:
all the numbers are multiples of each two.
For example,
2×2=4,
4×2=8,
8×2=16
So, the line would be linear.
// have a great day //
What is the value of p?
Answer:
[tex]p = 43 \: \: \: degrees[/tex]
Answer A is correct
Step-by-step explanation:
[tex]90 + p = 133[/tex]
the sum of the exterior angles in a triangle is equal to the sum of opposite interior angles.
[tex]p = 133 - 90 \\ p =4 3 \: \: \: degrees[/tex]
hope this helps
brainliest appreciated
good luck! have a nice day!
slove for g : 9+3.5g=11-0.5g
Answer:
g= 1/2
Step-by-step explanation:
9+3.5g=11-0.5g
Add .5 g to each side
9+3.5g+.5g=11-0.5g+.5g
9+4g = 11
Subtract 9 from each side
9+4g-9 = 11-9
4g = 2
Divide by 4
4g/4 = 2/4
g= 1/2
What is the experimental probability that a 10th-grade student chosen at random has at least one, but no more than two, siblings? Round to the nearest whole percent. 65% 70% 75% 80%
Answer:
the experimental probability is 70%
Step-by-step explanation:
PLEASE HELP, TIMEDThe table shows the results of a survey in which 10th-grade students were asked how many siblings (brothers and/or sisters) they have.
What is the experimental probability that a 10th-grade student chosen at random has at least one, but no more than two, siblings?
To the nearest whole percent, the experimental probability is
a. 65%.
b. 70%
c. 75%
d. 80%
We are given to find
the experimental probability that a 10th-grade student chosen at random has at least one, but no more than two, siblings
we know that
probability = ( number of favourable outcomes)/ ( total possible outcomes)
a 10th-grade student chosen at random has at least one, but no more than two, siblings
so, there can be one or two siblings
so, total number of such students =18+10=28
Number of favourable outcomes =28
total number of students =4+18+10+8=40
so, total favourable outcomes =40
now, we can find probability
[tex]p=\frac{28}{40}\\\\p=\frac{28}{40}\times 100\\\\p=70[/tex]
So,
Therefore, the experimental probability is 70%
Answer:
answer is B
or 70%
A box contains 5 yellow balls, 3 blue, and 1 red ball. Two balls are drawn at random. Find the probability that the two balls are yellow
Answer:
5/18
Step-by-step explanation:
5/9 times 1/2
5/18
I may be wrong sorry
Lianne drew a sphere with a radius of 7 in. She calculated its volume and wrote it below.
Answer:
1372
Step-by-step explanation:
4x7x7x7=1372:v=4/3 pi r^3
Therefore, 1372 is the value that should be multiplied by Pi in the numerator to correctly show the volume of the sphere.
please mark me brainliest :)
part 2. Find the measure of the indicated angle to the nearest degree
Answer:
i hope this helps you
Which expressions are equivalent to select three option. HURRY PLZ
Answer:
[tex] \sqrt{2^{2} } * \sqrt{2^{2} } * \sqrt{2} * \sqrt{5} * \sqrt{7} * \sqrt{y^{2} } * \sqrt{y} [/tex]
[tex] 2*2*y\sqrt{2*5*7*y} [/tex]
[tex] 4y\sqrt{70y} [/tex]
Step-by-step Explanation:
To find the expressions that are equivalent to
[tex] \sqrt{1,120y^{3} } [/tex]
let's simplify each of the options given to know if we would arrive at
[tex] \sqrt{1,120y^{3} } [/tex]
Option 1:
[tex] \sqrt{2*2*2*2*5*7*y*y} [/tex]
[tex] \sqrt{(2*2*2)*(2*5)*(7)*(y*y)} [/tex]
[tex] \sqrt{8*10*7*y^{2} } [/tex]
[tex] \sqrt{560y^{2} } [/tex]
Not equivalent to the given expression.
Option 2:
[tex] \sqrt{2^{2} } * \sqrt{2^{2} } * \sqrt{2^{2} } * \sqrt{5^{2} } * \sqrt{7^{2} } * \sqrt{y^{2} } * \sqrt{y^{2} } [/tex]
[tex] 2 * 2 * 2 * 5 * 7 * y * y [/tex]
[tex] 8*5*7*y*y [/tex]
[tex] 280y^{2} [/tex]
Not equivalent to the given expression.
Option 3:
[tex] \sqrt{2^{2} } * \sqrt{2^{2} } * \sqrt{2} * \sqrt{5} * \sqrt{7} * \sqrt{y^{2} } * \sqrt{y} [/tex]
[tex] 2 * 2 * \sqrt{2} * \sqrt{5} * \sqrt{7} * y * \sqrt{y} [/tex]
[tex] 2 * 2 * y * \sqrt{2} * \sqrt{5} * \sqrt{7} * \sqrt{y} [/tex]
[tex] 4y * \sqrt{2 * 5 * 7 * y} [/tex]
[tex] \sqrt{16y^{2} } * \sqrt{70y} [/tex]
[tex] \sqrt{16 * y^{2} * 70 * y } [/tex]
[tex] \sqrt{16 * 70 * y^{2} * y } [/tex]
[tex] \sqrt{1,120y^{3} } [/tex]
This option is equivalent.
Option 4:
[tex] 2*2*y\sqrt{2*5*7*y} [/tex]
[tex] 4y\sqrt{70y} [/tex]
[tex] \sqrt{16y^{2} } * \sqrt{70y} [/tex]
[tex] \sqrt{16 * y^{2} * 70 * y } [/tex]
[tex] \sqrt{1,120y^{3} } [/tex]
This option is equivalent to the given expression.
Option 5:
[tex] 4y\sqrt{70y} [/tex]
[tex] \sqrt{16y^{2} } * \sqrt{70y} [/tex]
[tex] \sqrt{16y^{2} * 70 * y} [/tex]
[tex] \sqrt{16 * 70 * y^{2} * y} [/tex]
[tex] \sqrt{1,120y^{3} } [/tex]
Equivalent!
Options 3, 4 and 5 are the 3 expressions equivalent to
[tex] \sqrt{1,120y^{3} } [/tex]
Answer:C D E
Step-by-step explanation:
Just did the test
What is the value of x?
20
35
60
70
HURRY PLEASE!!!!
Answer: 20
Step-by-step explanation:
Since these are vertical angles, they are equal to each other.
x+40=3x
40=2x
x=20
state what additional information is required in order to know that the triangles are congruent by SSS
Answer: d) DF ≅ JH
Step-by-step explanation:
Side-Side-Side Congruency Theorem states that triangles are congruent if and only if their corresponding side lengths are congruent.
Given: EF ≅HI
Given: DE ≅IJ
Missing: DF ≅ JH
LMN is a right triangle. True or False
Answer:
False
Step-by-step explanation:
Let us check using Pythagorean Theorem
[tex]c^2 = a^2 + b^2[/tex]
Where c is the hypotenuse (14), a is the base (13) and b is the perpendicular (5)
Putting in the above formula
[tex]14^2 = 13^2 + 5^2[/tex]
196 = 169+25
196 ≠ 194
So, It is not a right angled triangle
Find the volume of a cone. Either enter an exact answer in terms of or use 3.14 for pi and round your final answer to the nearest hundredth. The radius is 2 the height is 9
Answer:
12 units³
Step-by-step explanation:
The required formula is V = (1/3)πr²h, where r is the radius and h is the height. Here we get:
V = (1/3)π(2)²(9) = (1/3)π(9)(4) = 12 units³
Select all that apply.
Which of the following name a line in the drawings
Answer:
DB
It's the only line that is not a segment.
Step-by-step explanation:
Hhhhhhheeeeelllllpppppppp
Answer:
tan 41 = 0.87
sin 63 = 0.89
cos 14 = 0.97
Step-by-step explanation:
No explanation since the question states to use the ALEKS calculator so you just make sure the calculator is in degrees then simply press tan 41 etc.
Find the value of x
Answer:
The answer is 9
Step-by-step explanation:
56+(3x+7)=90 (In the picture it shows a 90 degree angle.)
Then, you can start solving the equation.
90-56=34
3x+7=34 (Subtract by 7)
3x=27 (Divide by 3 on both sides)
x=9
Given the function ƒ(x) = 8x^2 − 14x − 10, find ƒ(−2). A) ƒ(−2) = 50 B) ƒ(−2) = 60 C) ƒ(−2) = −6 D) ƒ(−2) = −70
Answer:
50
Step-by-step explanation:
f(x) = 8x² - 14x - 10
f(-2) = 8(-2)² - 14(-2) -10
f(-2) 8*4 + 28 - 10
f(-2) = 32 + 28 - 10 = 50
Please answer correctly !!!!!! Will mark brainliest !!!!!!!!!!!
Answer:
25
Step-by-step explanation:
So find the number that is a perfect square and 2 times the square root = 10
The number is 25.
Check:
[tex](x+5)^2=x^2+10x+25[/tex]
Answer:
The answer is 25.
Step-by-step explanation:
25 is a perfect square of 5. When x are added together, they form 10x.
[tex] {(x + 5)}^{2} [/tex]
[tex] {x}^{2} + 2(x)(5) + {5}^{2} [/tex]
[tex] {x}^{2} + 10x + 25[/tex]
Find the angle A if angle B is 60 degrees and angle A and angle B are complementary
Answer:
30 degrees
Step-by-step explanation:
Complimentary = 90 degrees
90 - 60 = 30 degrees
Which statement is true about quadrilateral QRST? Side QR has a length of 5 units. Side RS has a length of units. Side ST has a length of 6 units. Side TQ has a length of units.
Answer: side TQ 17 units
Step-by-step explanation:
Answer:
D.
Step-by-step explanation:
A car costs £15000. Work out the price after a 13% discount.
Answer:
13, 050
Step-by-step explanation:
15,000 by 13% = 1,950
15,000-1,950= 13, 050
Which algebraic expression represents this mathematical statement?
75 less than a number
O A. 75-n
O B. n-75
O C. n: 75
O D. n+ 75
Answer:
B
Step-by-step explanation:
Subtraction mean how much less than a number
A number is increased by 2 and then multiplied by 3. The result is 24. What is this number
Answer:
The answer is 6.
Step-by-step explanation:
To find this answer, divide 24 by 3 and you get 8. 8 minus 2 is 6.