Answer:
The answer to this question is 4.
Write the recurring decimal 0.25 as a fraction in its simplest form
Answer:
1/4 because 25% is a quarter.
A textbook store sold a combined total of 402 biology and physics textbooks in a week. The number of physics textbooks
sold was 54 less than the number of biology textbooks sold. How many textbooks of each type were sold?
Number of biology textbooks sold: 0
Number of physics textbooks sold:
0
We have two types of textbooks. Let's use "x" to represent the number of math textbooks and "y" to represent the number of history textbooks.
Altogether, the bookseller sold 240 math and history textbooks. So:
x + y = 240
Now, the number of history textbooks sold was 72 less than the number of math books sold. So:
y = x - 72
Now we can substitute for y in the equation and solve:
x + y = 240
x + (x - 72) = 240
2x - 72 = 240
2x = 312
x = 156
The bookseller sold 156 math textbooks.
Since y = x - 72, he must have sold 84 history textbooks.
Let's check our answers:
x + y = 240
156 + 84 = 240
That is true, so we did get the correct answers.
HELP THIS IS DUE
Solve the linear equation and figure out whether it’s one solution, infinite or no solution include steps
3/4x -7 = 3 (1/6x +1)
Answer:
Includes Steps
Step-by-step explanation:
3/4x-7 =3(1/6x+1)
3/4x-7=3/6x +3
1/4x=10
x=40
An investigator compares the durability of two different compounds used in the manufacture of a certain automobile brake lining. A sample of 212 brakes using Compound 1 yields an average brake life of 47,895 miles. A sample of 180 brakes using Compound 2 yields an average brake life of 49,767 miles. Assume that the population standard deviation for Compound 1 is 1590 miles, while the population standard deviation for Compound 2 is 4152 miles.
1. Determine the 90% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2.
2. Find the point estimate for the true difference between the population means.
Answer:
1. The 90% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2 is (-2411.84, -1332.16).
2. The point estimate for the true difference between the population means is of -1872.
Step-by-step explanation:
Before building the confidence interval, we need to understand the central limit theorem and subtraction between normal variables.
Central Limit Theorem
The Central Limit Theorem estabilishes 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.
Subtraction of Normal Variables:
When two normal variables are subtracted, the mean is the subtraction of the means while the standard deviation is the square root of the sum of the variances.
A sample of 212 brakes using Compound 1 yields an average brake life of 47,895 miles. The population standard deviation for Compound 1 is 1590 miles.
This means that [tex]\mu_1 = 47895, \sigma_1 = 1590, n = 212, s_1 = \frac{1590}{\sqrt{212}} = 109.2[/tex]
A sample of 180 brakes using Compound 2 yields an average brake life of 49,767 miles. The population standard deviation for Compound 2 is 4152 miles.
This means that [tex]\mu_2 = 49767, \sigma_2 = 4152, n = 180, s_2 = \frac{4152}{\sqrt{180}} = 309.47[/tex]
True difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2.
This is the distribution 1 - 2. So
[tex]\mu = \mu_1 - \mu_2 = 47895 - 49767 = -1872[/tex]
This is also the point estimate for the true difference between the population means, which is question 2.
[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{109.2^2+309.47^2} = 328.17[/tex]
90% confidence interval
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.9}{2} = 0.05[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.05 = 0.95[/tex], so Z = 1.645.
Now, find the margin of error M as such
[tex]M = zs = 1.645*328.17 = 539.84[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is -1872 - 539.84 = -2411.84
The upper end of the interval is the sample mean added to M. So it is -1872 + 539.84 = -1332.16.
The 90% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2 is (-2411.84, -1332.16).
17. Stella is competing in a diving competition. Her height in feet above the water is
modeled by the function h=-16t? + 8t + 48, where t is the time in seconds after she jumps
from the diving board. At what time will Stella land in the water? (Round to the nearest
hundredth, if necessary.)
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Answer:
after 2 seconds
Step-by-step explanation:
We want to find t such that h = 0.
0 = -16t² +8t +48
0 = 2t² -t -6 . . . . . . . divide by -8
0 = (t -2)(2t +3) . . . . factor
The only positive solution is t = 2, which makes the first factor zero.
Stella will land in the water at t = 2 seconds.
What is the equation of the circle, with center (4, 2) and radius 5 units?
Answer:
Step-by-step explanation:
Let us begin by just getting the equation of the circle first.
(x - 4)^2 + ( y - 2)^2 = 5^2
(x - 4)^2 + ( y - 2)^2 = 25
Now I'm going to graph that equation and discuss it here.
I have graphed the second equation above.Notice that the center is at (4,2) just as the question requested.A second point was put at (4,7). That was to show you that the radius is 5 units. You can calculate that it is 5 units by noticing that 7 - 2 = 5 So the distance from the center to (4,7) is 5 units which is the amount of the radius.Notice that the numbers representing the center have been reversed in sign. That is always done for a circle. The center's coordinates are always the negative of the coordinates given. You will be told why later.Please answer this hurry up thank you so much!
x-1 = 9
one step equation
Answer:
x=10
Step-by-step explanation:
x-1 = 9
add 1 on both side
x-1+1=9+1
x=10
Answer:
The answer would be 10
Step-by-step explanation:
1) Add 1 to both sides.
[tex]x = 9 + 1[/tex]
2) Simplify 9 + 1 to 10.
[tex]x = 10[/tex]
Hence, the answer would be 10.
x = 10
The five members of the Roberts family went to a high school soccer game. The total cost was $44.
They paid $10 less because they used a $10 coupon, how much was the cost per person?
Answer:
%6.8
Step-by-step explanation:
The five members of the Roberts family went to a high school soccer game. The total cost was $44.
They paid $10 less because they used a $10 coupon, how much was the cost per person?
members in the family = 5
total cost = $44
cost per person = 44/5
= $8.8
Now, they got $10 coupon so they paid $10 less.
therefore,
New total cost = $44-$10
= $34
New per person cost = $34/5
= $6.8
Answer:
they paid $8.80 cents per person without coupan but with coupon they paid $6.80
Step-by-step explanation:
i divied 44 by 5 to get $8.80 without cupon but woth coupan is subracted 34 divied by 5 and got $6.80.
1 1/4 x 1 1/3 plsss help
Answer:
exact form: 5/3
decimal form: 1.6 (6 is repeating)
mixed number form: 1 2/3
Step-by-step explanation:
Answer:
1 2/3
Step-by-step explanation:
1 1/4 x 1 1/3 = 5/4 x 4/3 = (5x4)/(4x3) = 20/12 = 5/3 = 1 2/3
How many solution(s) does the equation x2 - 6x + 6 = -3 have?
Answer:
2 solutions
Step-by-step explanation:
PLEASE HELPPP!!!
The picture is there
Answer:
Its also 30 degrees
Step-by-step explanation:
That shape is a vertical angle. This means that is 2 was 150 degrees, than 4 would also be 150 degrees. This means that if 1 is 30, then 3 is...... eh you get the idea. its 30 degrees.
P.S: Your welcome :)
Write an equation that can be used to find the nth term of the sequence, an.
70, 103, 136, 169, 202, ...
Enter your answer by filling in the boxes.
an = __n + __
Answer:
+12 +1
Step-by-step explanation:
Answer:
an = 33n + 37
Step-by-step explanation:
I took the test.
Measurement of a circle
(Giving brainliest for the correct answer)
Answer:
A. [tex] \frac{5}{6}\pi x^2 [/tex]
Step-by-step explanation:
Central angle of shaded part
[tex] \theta = 360\degree-60\degree= 300\degree[/tex]
Radius (r) = x unit
Area of the shaded part of [tex] \odot K[/tex]
[tex] = \frac{\theta}{360\degree} \times \pi r^2 [/tex]
[tex] = \frac{300\degree}{360\degree} \times \pi x^2 [/tex]
[tex] = \frac{5}{6}\pi x^2 [/tex]
If The difference of a number and ten is tripled, the result is 4 more than the number. Find the number
Answer:
x=13
Step-by-step explanation:
3(x-10)=x+4
3x-30=x-4
3x=x+26
2x=26
x=13
Which values should you plot to show a linear relationship?
Month Population
Log(population)
1
1400
3.146
2
2600
3.415
3
4700
3.672
4
9000
3.954
5
17000
4.230
6
32000
4.505
O A. "Population on the x-axis and "Log(population)" on the y-axis.
O B. "Month" on the x-axis and "Population" on the y-axis.
w
O C. "Month" on the x-axis and "Log(population)" on the y-axis.
O D. "Log(population)" on the x-axis and "Month" on the y-axis.
Answer:“ C ”
“month” on the x axis and “log” on the y axis
A diamond retailer buys a ring from his supplier
for $875. He marks up the price 110% to sell in
his store. What is the selling price of the
diamond with a 6% sales tax?
Answer:
nerd is 18
Step-by-step explanation:
xsas
Answer: $1,947.75
Step-by-step explanation: First, the mark up is 110% of the total, which is $875. 110% of 875 is $962.50, which you add to the total ($875) since it is mark up. $962.50 + $875 = $1837.50. Finally, 6% of $1837.50 is $110.25 so you add this to your new price ($1837.50) since the 6% is the sales tax. $1837.50 + $110.25 = $1947.75
In a bag are 3 red, 9 blue, 2 yellow and 3 green marbles. If you draw out a marble at random, what the probability that you will draw a blue marble? P(blue)
Question 2 options:
3/17
9/17
2/17
14/17
Answer:
9/17
Step-by-step explanation:
there are 17 marbles in total 9 of them are blue therefore, 9/17 is the correct answer
2. Use the distributive property to write an expression that is equivalent to 5(-2x-3)
Answer:
-10x-15
Step-by-step explanation:
So first we start off with 5(-2x-3)
Next, we distribute the 5 to the -2x to get -10x.
Next, we distribute the 5 to the -3 to get -15.
Therefore,
-10x-15 is correct
Answer:
-10x-15
Step-by-step explanation:
It's 10x-15, because you just need to simplify it.
It is the same thing as (5 x (-2x)) - (5 x 3), if you use the distributive property.
that is the same as -10x-15
The width of a rectangular tank is x cm . It's height is 2/3 it's width and it's length is four times it's height .The volume of the tank in litres is
Answer:
Tank is a tank and a cat is a cat.
Step-by-step explanation:
16. Find the slope and y-intercept of y - y° = m(x – x°) where x° and y°
are constants.
Step-by-step explanation:
Slope = m
y - y° = m(x - x°)
m(x - x°) = y - y°
m = (y - y°)/(x - x°)
y intercept x = 0
... and I don't know :")
If there are 36 boys and 48 girls in a room, fill out all of the possible ratios of boys to girls that could be made.
Answer:
ans
Step-by-step explanation:
possible ratios are 3:4,9:12 and 18:24
Mark me as a brain list please
Answer:
Step-by-step explanation:
12:9
8:6
4:3
16:12
24:18
48:36
In the spinner below, what is the probability of landing on 5?
A.2/6
B.1/4
C.1/8
D.1/12
Solve the equation
16x2 + 4x + 1 =0
Answer:
X= -33/4
Step-by-step explanation:
a rectangular window is 36 inches long and 24 in wide. tammy would like to buy a screen for the window. because of the screen is based on the number of square feet the screen is use the fraction to find the area of the window in square feet.
Answer:
144 Sq
Step-by-step explanation:
The area of the rectangle formula is Length x Width. Given 4 ft and 3 ft, we can find the area. The screen would be 12 Sq. Feet since the question is asking for inches we must now convert this.
a ribbon is 4m long. how many pieces each of 30cm long can be cut from the ribbon
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Answer:
13
Step-by-step explanation:
4 m is 400 cm, so the number that can be cut is ...
(400 cm)/(30 cm/piece) = 13 1/2 pieces
13 pieces can be cut that are 30 cm long.
Answer:
13 whole pieces
Step-by-step explanation:
4m=400cm
400cm÷30cm=13.333333
you can't get 0.33333333(goes on forever) of a ribbon so its 13
hope this helps:)
PLEASE HELPPPP
Simplify: 2/3 -(6 + 3x) + 3 (x - 1)
Answer:
-25/3, or - 8 1/3
Step-by-step explanation:
many steps
2/3 + - (6+3x)/1 +3 (x-1)
- (6+3x)/1 *3/3* 2/3+ -(6+3x)/1 * 3/3 + 3 (x-1)
- (6+3x/1* 3/3* 2/3+ -(6+3x)*3/3 +3(x-1)*3/3
2-(6+3x)*3+3(x-1)*3/3
2+ (-1*6 - (3x)0 * 3+3 (x-1)*3/3
-1*6*2+(-6-(3x))*3+3(x-1)*3/3
3* -1 *2 + (-6-3x) *3+3 (x-1) *3 / 3
3*-1 * 2+(-6-(3x)) *3+3(x-1)*3/3
2-6*3x*3+3(x-1)*3/3
-6*3*2-18-3x*3+3(x-1)*3/3
3*-3*2-18-9x+3(x-1)*3/3
Can someone tell
Me how to do this
Is this a Percent Increase or Decrease Problem?
Kemyah bought a necklace for $260 that was marked
up by 30%.
Answer:
increase
Step-by-step explanation:
....................
Answer:
Percent Increase
Step-by-step explanation:
Percent Increase because if the necklace was bought for $260, and was marked up by 30%, it means it was originally a lower price, that was multiplied by 130%.
Explanation by algebra:
x + 0.30x = 260
1.3x = 260
x = 260/1.3
x = 200
The necklace was originally $200, and it was marked up by 30$, making it $260.
Out of a total of N students at a school, the number of students who have seen a new television program increases at a rate proportional to the product of the number of students who have seen the program and the number of students who have not seen the program. If S denotes the number of students who have seen the program at time t, which of the following differential equations could be used to model this situation, where k is a positive constant?
a. ds/dt = KS
b. ds/dt = kt(N-t)
c. ds/st = KS(N-S)
d. ds/dt = KS(S-N)
Answer:
ds/dt = kN(N-S)
Step-by-step explanation:
Given
Total number of student = N
number of students who have seen the program = S
Number of students who have not seen the program = N-S
The product of the number of students who have seen the program and the number of students who have not seen the program = N(N-S)
If the rate of number of students who have seen a new television program increases at a rate proportional to the product of the number of students who have seen the program and the number of students who have not seen the program, then:
ds/dt = kN(N-S)
k is the proportionality constant
