Answer:
Hes correct ^
Step-by-step explanation:
Two trains are 500 miles apart when they first start moving towards each other. If in two hours the distance between them is 300 miles and one train goes 20 miles faster than another, find the speed of the faster train. (Note: there are two possible solutions. Could you please find both?)
Answer:
Step-by-step explanation:
They travel 500 - 300 = 200 miles in 2 hours so their combined speed is
100 mph.
If their respective speed are x and y mph then we have the system
x + y = 100
x - y = 20
Adding the 2 equations
2x = 120
x = 60
and y = 40.
The other solution is that y = 60 mph and x = 40 mph.
Every high school senior takes the SAT at a school in St. Louis. The high school guidance director at this school collects data on each graduating senior’s GPA and their corresponding SAT test score. The guidance director is conducting a _________ in this experimental design.
A. sample survey
B. census
C. sample poll
D. random sample
The guidance director is conducting a sample poll in this experimental design.
What is sample?Sample is a part of population. It does not comprises whole population. It is representatitive of whole population.
How to fill blank?We are required to fill the blank with appropriate term among the options.
The correct option is sample poll because the guidance director collects data in his school only.
Census collects the whole population of the country.
Sample poll means collecting data from small population.
Random sample means collecting data from a part of popultion without identifying any variable.
Hence we found that he was doing sample poll.
Learn more about sample at https://brainly.com/question/24466382
#SPJ2
Let a submarine be at a constant depth of 5 km. It is headed in the direction of a lighthouse. If the distance between the submarine and the base of the lighthouse is decreasing at a rate of 24 km/h when the sub is 13 km away from the base, then what is the speed of the submarine
Answer:
24 km/h
Step-by-step explanation:
Given:
Constant speed of submarine = 24 km/h
Depth under sea = 5 km
Distance of submarine from lighthouse = 13 km
Find:
Speed of the submarine
Computation:
At steady speed, the distance between both the submarine and the lighthouse base decreases at a rate of 24 km/hr.
So, when it is 13 kilometres from its starting point, the speed remains constant at 24 kilometres per hour.
Is it true that every whole number is a solution of x > 0? Use complete sentences to explain your reasoning.
Whole numbers are natural numbers, and natural numbers do not include negatives, decimals, fractions, or roots, so all whole numbers can indeed satisfy the inequality.
Two mechanics worked on a car. The first mechanic worked for 10 hours, and the second mechanic worked for 5 hours. Together they charged a total of
$750. What was the rate charged per hour by each mechanic if the sum of the two rates was $105 per hour?
Step-by-step explanation:
let's convert the statement into equation..
let the charge of 1st mechanic be x and second be y..
by the question..
10x+5y=750...(i)
x+y=105..(ii)
from eqn(ii)..
x+y=105
or, x=105-y...(iii)
substituting the value of x in eqn (i)..
10x+5y=750
or, 10(105-y)+5y=750
or, 1050-10y+5y=750
or, 1050-750=5y
or, y=300/5
•°• y=60
substituting the value of y in eqn(iii).
x=105-y
or, x=105-60
•°• x= 45..
the rate charged by two mechanics per hour was 60$ and 45$
At a large Midwestern university, a simple random sample of 100 entering freshmen in 1993 found that 20 of the sampled freshmen finished in the bottom third of their high school class. Admission standards at the university were tightened in 1995. In 1997, a simple random sample of 100 entering freshmen found that only 10 finished in the bottom third of their high school class. Let p 1 and p 2 be the proportions of all entering freshmen in 1993 and 1997, respectively, who graduated in the bottom third of their high school class. What is a 90% plus four confidence interval for p 1 – p 2?
Answer:
The 90% confidence interval for the difference of proportions is (0.01775,0.18225).
Step-by-step explanation:
Before building the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
p1 -> 1993
20 out of 100, so:
[tex]p_1 = \frac{20}{100} = 0.2[/tex]
[tex]s_1 = \sqrt{\frac{0.2*0.8}{100}} = 0.04[/tex]
p2 -> 1997
10 out of 100, so:
[tex]p_2 = \frac{10}{100} = 0.1[/tex]
[tex]s_2 = \sqrt{\frac{0.1*0.9}{100}} = 0.03[/tex]
Distribution of p1 – p2:
[tex]p = p_1 - p_2 = 0.2 - 0.1 = 0.1[/tex]
[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.04^2 + 0.03^2} = 0.05[/tex]
Confidence interval:
[tex]p \pm zs[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
90% confidence level
So [tex]\alpha = 0.1[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].
The lower bound of the interval is:
[tex]p - zs = 0.1 - 1.645*0.05 = 0.01775 [/tex]
The upper bound of the interval is:
[tex]p + zs = 0.1 + 1.645*0.05 = 0.18225 [/tex]
The 90% confidence interval for the difference of proportions is (0.01775,0.18225).
Elena drank 3 liters of water yesterday. Jada drank 3/4 times as much water as elena. Link drank twice as much as Jada. Did jada drink more or less then elena? Explain how you know
Answer:
Step-by-step explanation:
3\4 bc on a nuberline it would be 3 3\4
I--I----(etc)
so yeah hope i helped
Solve the formula for the given variable.
-2x - 6 = 4x
Please helppp
Answer:
s snsnnssjsjjsnsnsjs
es 17 es
State two similarities and one difference between the graphs of f(x)= 3^x and g (x)= (1/3) ^x
Find the lengths of AD, EF, and BC in the trapezoid below.
We know that,
[tex]EF=\dfrac{AD+BC}{2}[/tex]
which is
[tex]x=\dfrac{x-5+2x-4}{2}[/tex]
Now solve for x,
[tex]x=\dfrac{3x-9}{2}[/tex]
[tex]2x=3x-9[/tex]
[tex]x=9[/tex]
Since x is 9, the lengths are,
[tex]AD=x-5=9-5=\boxed{4}[/tex]
[tex]EF=x=\boxed{9}[/tex]
[tex]BC=2x-4=18-4=\boxed{14}[/tex]
Hope this helps :)
Please help on my hw
Answer:
Base is 3 centimeter and hight is 12 cent.
What are the coordinates of point K?
A (-2,4)
B (-2,-4)
C (2,-4)
D (2, 4)
Answer:
A
Step-by-step explanation:
I guess that is the answer
Find the value of x.
X 9 9 7 x = [?]
Tom and Jerry had a race. Tom started at 0200 running at 4.5km per hour. Jerry started
later at 6:30am running at 6.5km per hour. After five hours, who was ahead, and by how
much (answer in kilometres)
Answer:
Tom, 10.25
Step-by-step explanation:
Distance covered by Tom=4.5*(4 1/2+5)=81/4=42.75km
Distance covered by Jerry=6.5*(5)=32.5km
Tom is ahead from Jerry by 10.25km
write the equation of the graph, y=? SOMEBODY PLEASE HELP
Answer:
[tex]y=\left(6\right)^{x}\ -3[/tex]
Step-by-step explanation:
What number x gives maximum value for c(12,x)?
Answer:
i will say methods try yourself:
How to Determine Maximum Value
How to Determine Maximum ValueIf your equation is in the form ax2 + bx + c, you can find the maximum by using the equation:
How to Determine Maximum ValueIf your equation is in the form ax2 + bx + c, you can find the maximum by using the equation:max = c - (b2 / 4a).
How to Determine Maximum ValueIf your equation is in the form ax2 + bx + c, you can find the maximum by using the equation:max = c - (b2 / 4a).The first step is to determine whether your equation gives a maximum or minimum. ...
How to Determine Maximum ValueIf your equation is in the form ax2 + bx + c, you can find the maximum by using the equation:max = c - (b2 / 4a).The first step is to determine whether your equation gives a maximum or minimum. ...-x2 + 4x - 2.
How to Determine Maximum ValueIf your equation is in the form ax2 + bx + c, you can find the maximum by using the equation:max = c - (b2 / 4a).The first step is to determine whether your equation gives a maximum or minimum. ...-x2 + 4x - 2.Since the term with the x2 is negative, you know there will be a maximum point.
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plzz follow and make brainlist
what is the simple definition of realnumbers
Answer:
In mathematics, a real number is a value of a continuous quantity that can represent a distance along a line (or alternatively, a quantity that can be represented as an infinite decimal expansion).
In 10 words or fewer, what is the square root of -9?
Type answer here...
What is the square root of -9
Answer:
no solution
Step-by-step explanation:
a negative number cannot be square rooted
Answer:
"not possible". no such thing as a negative squared number
What is the slope of the line that passes through the points (-7, -4) and
(-11, -2)? Write your answer in simplest form.
Answer:
-1/2
Step-by-step explanation:
We can use the slope formula
m = ( y2-y1)/(x2-x1)
= ( -2 - -4)/( -11 - -7)
=( -2+4)/( -11+7)
= 2 / -4
= -1/2
in triangle JKL, angle JKL is a right angle, line KM is an altitude, JL=20, ML=4. Find KM
9514 1404 393
Answer:
KM = 8
Step-by-step explanation:
The ratio of long side to short side is the same for all of the triangles in this geometry:
KM/ML = JM/KM
KM² = ML·JM = 4(20-4) = 64
KM = √64 = 8
The length of KM is 8 units.
Which graph represents the function h(x) = |x – 3|?
On a coordinate plane, an absolute value graph has a vertex at (0, 3).
On a coordinate plane, an absolute value graph has a vertex at (0, negative 3).
On a coordinate plane, an absolute value graph has a vertex at (3, 0).
On a coordinate plane, an absolute value graph has a vertex at (negative 3, 0).
Answer:
option 3
Step-by-step explanation:
i know because i got it right.
22. The ratio in which (4, 5) divides the join of (2, 3)
and (7, 8) is :
(a) 4 : 3
(c) 3 : 2
(b) 5:2
(d) 2:3
Let the ratio be m:n
(x,y)=(4,5)Points be (x1,y1)=(2,3)(x2,y2)=(7,8)We know
[tex]\boxed{\sf (x,y)=\left(\dfrac{mx_2+nx_1}{m+n},\dfrac{my_2+ny_1}{m+n}\right)}[/tex]
[tex]\\ \sf\longmapsto (4,5)=\left(\dfrac{7m+2n}{m+n},\dfrac{8m+3n}{m+n}\right)[/tex]
Now
.[tex]\\ \sf\longmapsto \dfrac{7m+2n}{m+n}=4\dots(1)[/tex]
[tex]\\ \sf\longmapsto \dfrac{8m+3n}{m+n}=5\dots(2)[/tex]
Adding both
[tex]\\ \sf\longmapsto \dfrac{7m+2n+8m+3n}{m+n}=4+5[/tex]
[tex]\\ \sf\longmapsto \dfrac{7m+8m+2n+3n}{m+n}=9[/tex]
[tex]\\ \sf\longmapsto \dfrac{15m+5n}{m+n}=9[/tex]
[tex]\\ \sf\longmapsto 15m+5n=9(m+n)[/tex]
[tex]\\ \sf\longmapsto 15m+5n=9m+9n[/tex]
[tex]\\ \sf\longmapsto 15m-9m=9n-5n[/tex]
[tex]\\ \sf\longmapsto 6m=4n[/tex]
[tex]\\ \sf\longmapsto \dfrac{m}{n}=\dfrac{6}{4}[/tex]
[tex]\\ \sf\longmapsto \dfrac{m}{n}=\dfrac{3}{2}[/tex]
[tex]\\ \sf\longmapsto m:n=3:2[/tex]
Option B is correct
Find the distance between the points (-4, -2) and (-8, 6)
Answer:
distance=√[(x2-x1)²+(y2-y1)²]
√[{6-(-2)}²+ (-8-(-4))²]
√(64+16)
√[100]
10
Points given
(-4,-2)(-8,-6)Distance:-
[tex]\\ \sf \longmapsto \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]
[tex]\\ \sf \longmapsto \sqrt{(-8+4)^2+(6+2)^2}[/tex]
[tex]\\ \sf \longmapsto \sqrt{(-4)^2+(8)^2}[/tex]
[tex]\\ \sf \longmapsto \sqrt{64+16}[/tex]
[tex]\\ \sf \longmapsto \sqrt{80}[/tex]
[tex]\\ \sf \longmapsto 8.4[/tex]
The king and queen spent $1500 on decorations for the ball +8 dollars per guest for party favors. The king and queen are charging each guest $12 to enter the dance. How many guests must come to the ball for the king and queen to break even? (you must write an equation and then solve)
Answer:
375 guests
Step-by-step explanation:
costs: 1500 + 8g
income: 12g
They must be equal
1500+8g = 12g
Subtract 8g from each side
1500 +8g-8g =12g-8g
1500= 4g
Divide by 4
1500/4 = 4g/4
375 = g
In a particular year, a total of 46,601 students studied in two of the most popular host countries when traveling abroad. If 8483 more students studied in the most popular host country than in the second most popular host country, find how many students studied abroad in each country. There were ____ students who studied abroad in the most popular host country.
Answer:
31,783.5
Step-by-step explanation:
Half of 46601 = 23300.5
23300.5 + 8483 =31783.5
1. Đường kính của một loại trục máy là một đại lượng ngẫu nhiên có phân phối chuẩn N (μ = 250mm, σ2 = 25mm2). Trục máy được gọi là hợp quy cách nếu đường kính từ 245mm đến 255mm. Cho máy sản xuất 100 trục. Tính xác suất để:
a. Có 50 trục hợp quy cách.
b. Có không quá 80 trục hợp quy cách
Answer:
please ask in English
Step-by-step explanation:
then I can help
A vehicle purchased for $20700 depreciates at a constant rate of 6%.
Determine the approximate value of the vehicle 14 years after purchase.
Round to the nearest whole number.
Question Help: Viden M Message instructor
n Post to forum
Answer:
$22,000
Step-by-step explanation:
To make sky blue Sam uses two drops of blue paint for every eight drops of white paint. He wants to
make a large amount of sky blue paint. If he uses sixteen drops of blue, how many drops of white will he
need?
Answer:
64
Step-by-step explanation:
The Ratio of Blue to White drops is 2:8
16*4=64,... 16:64 Have a nice day!
Please help me with this on the picture
Answer:
1. 748
2. 901
3. 27
4. 672
Step-by-step explanation:
1. 1011-263=748
2. 653+248=901
3. 1161÷43=27
4. 48×14=672
Bob wants to replace a glass window in his restaurant. The window is in the shape of a square. Its side lengths are 6 feet. Suppose glass costs $7 for each square foot. How much will the glass cost to replace the window?
ANSWER: The glass window will cost $252.00 for window replacement.
EXPLANATION:
The area of a square is given by the formula:
s^2
where s is the side length.
If we were to replace the glass window, and it will cost $7.00 per square foot, the total price will be:
FIND AREA OF THE GLASS WINDOW:
6^2 = 36 square feet
$7 per square foot so:
36 x 7 = 252
Therefore it will cost $252.00 to replace the glass window.
