Answer:
(3,2)
Step-by-step explanation:
3x + 4y=17
- 4x – 3y= - 18
Multiply the first equation by 4
4(3x + 4y=17 )
12x +16y = 68
Multiply the second equation by 3
3( - 4x – 3y= - 18)
-12x -9y = -54
Add the new equations together to eliminate x
12x +16y = 68
-12x -9y = -54
-----------------------
7y = 14
Divide by 7
7y/7 = 14/7
y=2
Now find x
3x+4(2) = 17
3x+8 = 17
Subtract 8 from each side
3x+8-8 = 17-8
3x = 9
Divide by 3
x = 3
The time it takes to install a certain hardware is random. A technician installs this hardware on 64 computers with the average installation time being 42 minutes and the standard deviation of the times being 5 minutes. What is a 90% confidence interval for the popu
Answer:
[tex]40.97<\mu<43.03[/tex]
Step-by-step explanation:
Th formula for calculating the confidence interval of a population is expressed as shown;
CI = xbar ± Z*S/√n where;
xbar is the mean or average sample
Z is the z-score at 90% confidence
S is the standard deviation
n is the sample size
Given parameters
xbar = 42
Z at 90% CI = 1.645
S = 5
n = 64
Substituting the values into the formula will give;
CI = 42±(1.645*5/√64)
CI = 42±(1.645*5/8)
CI = 42±(1.645*0.625)
CI = 42±1.028125
CI = (42-1.028125, 42+1.028125)
CI = (40.971875, 43.028125)
Hence the 90% confidence interval for the population is approximately (40.97, 43.03) i.e [tex]40.97<\mu<43.03[/tex]
If a dog has 2,000,000 toys and he gives 900,000 away. Then gets 2,000 more, also looses 2,000,000. He's sad but then also got 5,000,000,000 more and gives 1,672,293 out. How much does he have now? And how much he gave away. And how much he got.
Answer:
See below.
Step-by-step explanation:
He does not have enough to loose 2,000,000 at that point, so this whole problem is nonsense.
Does the function satisfy the hypotheses of the Mean Value Theorem on the given interval? f(x) = 4x2 − 3x + 2, [0, 2]
Answer:
Yes , it satisfies the hypothesis and we can conclude that c = 1 is an element of [0,2]
c = 1 ∈ [0,2]
Step-by-step explanation:
Given that:
[tex]f(x) = 4x^2 -3x + 2, [0, 2][/tex]
which is read as the function of x = 4x² - 3x + 2 along the interval [0,2]
Differentiating the function with respect to x is;
f(x) = 8x - 3
Using the Mean value theorem to see if the function satisfies it, we have:
[tex]f'c = \dfrac{f(b)-f(a)}{b-a}[/tex]
[tex]8c -3 = \dfrac{f(2)-f(0)}{2-0}[/tex]
since the polynomial function is differentiated in [0,2]
[tex]8c -3 = \dfrac{(4(2)^2-3(2)+2)-(4(0)^2-3(0)+2)}{2-0}[/tex]
[tex]8c -3 = \dfrac{(4(4)-3(2)+2)-(4(0)-3(0)+2)}{2-0}[/tex]
[tex]8c -3 = \dfrac{(16-6+2)-(0-0+2)}{2-0}[/tex]
[tex]8c -3 = \dfrac{(12)-(2)}{2}[/tex]
[tex]8c -3 = \dfrac{10}{2}[/tex]
8c -3 = 5
8c = 5+3
8c = 8
c = 8/8
c = 1
Therefore, we can conclude that c = 1 is an element of [0,2]
c = 1 ∈ [0,2]
A test-preparation company advertises that its training program raises SAT scores by an average of at least 30 points. A random sample of test-takers who had completed the training showed a mean increase smaller than 30 points.
(a) Write the hypotheses for a left-tailed test of the mean.
(b) Explain the consequences of a Type I error in this context.
Answer:
(a) Null Hypothesis, [tex]H_0[/tex] : [tex]\mu \geq[/tex] 30 points
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] < 30 points
(b) Type I error is that we conclude that test-takers who had completed the training showed a mean increase smaller than 30 points but in actual, the program raises SAT scores by an average of at least 30 points.
Step-by-step explanation:
We are given that a test-preparation company advertises that its training program raises SAT scores by an average of at least 30 points.
A random sample of test-takers who had completed the training showed a mean increase smaller than 30 points.
Let [tex]\mu[/tex] = average SAT score.
(a) So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu \geq[/tex] 30 points
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] < 30 points
Here, the null hypothesis states that the training program raises SAT scores by an average of at least 30 points.
On the other hand, the alternate hypothesis states that test-takers who had completed the training showed a mean increase smaller than 30 points.
(b) Type I error states the probability of rejecting the null hypothesis given the fact that null hypothesis is true.
According to the question, the Type I error is that we conclude that test-takers who had completed the training showed a mean increase smaller than 30 points but in actual, the program raises SAT scores by an average of at least 30 points.
The consequence of a Type I error is that we conclude the test-takers have low SAT scores but in actual they have an SAT score of at least 30 points.
How many times does the digit 9 appear in the list of all integers from 1 to 500? (The number $ 99 $, for example, is counted twice, because $9$ appears two times in it.)
Answer:
95 times digit 9 appears in all integers from 1 to 500.
Step-by-step explanation:
No. of 9 from
1-9: 1 time
10-19: 1 time
20-29: 1 time
30-39: 1 time
40-49: 1 time
50-59: 1 time
60-69: 1 time
70-79: 1 time
80-89 : 1 time
from 90 to 99
there will be one in 91 to 98
then two 9 in 99
thus, no of 9 from 90 to 99 is 10
Thus, total 9's from 1 to 99 is 9+10 = 19
Thus there 19 9's in 1 to 99
similarly
there will be
19 9's in 100 to 199
19 9's in 200 to 299
19 9's in 300 to 399
19 9's in 400 to 499
Thus, total 9's will be
19 + 19 + 19+ 19 + 19 + 19 = 95
Thus, 95 times digit 9 appears in all integers from 1 to 500.
What is the equation of the following line? Be sure to scroll down first to see all answer options.
A.
y = - 1/2x
B.
y = 1/2x
C.
y = 2x
D.
y = -6x
E.
y = 6x
F.
y = 3x
Answer:
y=-6x
Step-by-step explanation:
Determine whether the sequence converges or diverges. If it converges, find the limit. (If an answer does not exist, enter DNE.)
an = (−3^n)/(4n!)
Answer:
[tex]a_{i} = \frac{(-3)^{i}}{4\cdot i!}[/tex] converges.
Step-by-step explanation:
The convergence analysis of this sequence is done by Ratio Test. That is to say:
[tex]r = \frac{a_{n+1}}{a_{n}}[/tex], where sequence converges if and only if [tex]|r| < 1[/tex].
Let be [tex]a_{i} = \frac{(-3)^{i}}{4\cdot i!}[/tex], the ratio for the expression is:
[tex]r =-\frac{3}{n+1}[/tex]
[tex]|r| = \frac{3}{n+1}[/tex]
Inasmuch [tex]n[/tex] becomes bigger, then [tex]r \longrightarrow 0[/tex]. Hence, [tex]a_{i} = \frac{(-3)^{i}}{4\cdot i!}[/tex] converges.
A computer password is required to be 7 characters long. How many passwords are possible if the password requires 3 letter(s) followed by 4 digits (numbers 0-9), where no repetition of any letter or digit is allowed
Answer:
[tex]78,\!624,\!000[/tex].
Step-by-step explanation:
Note the requirements:
Repetition of letter or digit is not allowed.The order of the letters and digits matters.Because of that, permutation would be the most suitable way to count the number of possibilities.
There are [tex]\displaystyle P(26,\, 3) = \frac{26!}{(26 - 3)!} = 26 \times 25 \times 24 = 15,\!600[/tex] ways to arrange three out of [tex]26[/tex] distinct letters (without replacement.)
Similarly, there are [tex]\displaystyle P(10,\, 4) = \frac{10!}{(10 - 4)!} = 10 \times 9 \times 8 \times 7= 5,\!040[/tex] ways to arrange four out of [tex]10[/tex] distinct numbers (also without replacement.)
Therefore, there are [tex]15,\!600[/tex] possibilities for the three-letter section of this password, and [tex]5,\!040[/tex] possibilities for the four-digit section. What if these two parts are combined?
Consider: if the first three letters of the password were fixed, then there would be [tex]5,\!040[/tex] possibilities. However, if any of the first three letters was changed, the result would be another [tex]5,\!040\![/tex] possibilities, all of which are different from the previous [tex]5,\!040\!\![/tex] possibilities. These two three-letter sections along will give [tex]2 \times 5,\!400[/tex] possibilities. Since there are [tex]15,\!600[/tex] three-letter sections like that, there would be [tex]15,\!600 \times 5,\!400 = 78,\!624,\!000[/tex] possible passwords in total. That gives the number of possible passwords that satisfy these requirements.
PLS HELP !!
Define two terms, each containing the variables x and y, with exponents on each. (For Example : 10x³y–⁵)Find the quotient of the two terms. Explain step-by-step how you found the quotient
Answer:
Step-by-step explanation:
Two such terms are 7x^3*y^9 and -3x*y^5
Their quotient is
7x^3*y^9
--------------
-3x*y^5
This can be simplified as follows:
The numerical coefficients become -7/3.
x^3/x = x^3*x^1 = x^(3 - 1) = x^2 (we subtract the exponent of x in the denominator from the exponent of x in the numerator).
Next, y^9*y^5 = y^4.
The quotient in final reduced form is then (-7/3)x^2*y^4
find the area of square whose side is 2.5 cm
Answer:
6.25
Step-by-step explanation:
2.5 *2.5=6.25
Answer:
6.25cm^2.
Step-by-step explanation:
To find the area of a square, you multiply the two sides, 2.5✖️2.5.
This gives the area of 6.25cm^2.
Hope this helped!
Have a nice day:)
which rate can you set 7 miles over 1 hour equal to in order to find the distance traveled in 49 hours at 7 miles per hour
Answer:
Step-by-step explanation:
time = 49 hours
speed = 7 miles/hour
speed = distance / time
∴ distance = speed × time
= 7 × 49
= 343 miles
To the nearest square inch, what is the surface area of the square pyramid shown in the image? A. 175 in.^2 B. 200 in.^2 C. 400 in.^2 D. 700 in.^2 Please show ALL work! :D
Answer: C. 400 in^2
Step-by-step explanation:
First find the surface area or the area of the base which is in the shape of a square and has a side length of 10 in. So square 10 to find the area.
Area of base: 10 * 10 = 100
Next find the area of one of the triangles.
As we could see the triangle has a slant height of 15 in and a base of 10. To find the area of a triangle we multiply the base times the height and multiply it by half.
Area of one triangle. 15 * 10 = 150 * 1/2 = 75
Since one side of the triangle has a surface area of 75 inches we will multiply it by 4 since there are four triangles to find the total surface area of the four faces.
75 * 4 = 300
We now know that the the 4 triangles surface area dd up to 300 so we will add it to the area of the base which is 100 to find the whole surface area of the figure.
300 + 100 = 400
What is the value of b.
C=25
s=9
B=4c-s2
Answer:
82
Step-by-step explanation:
Plug in the variables into the equation and solve for B but remember your order of operations when solving multiplication/division before addition/subtraction.
B = 4*25-9*2
B = 100-18
B = 82
What is the value of x?
Answer:
58
Step-by-step explanation:
By the property of intersecting secants outside of a circle, we have:
x° = 1/2( 141° - 25°) = 1/2 * 116° = 58°
Therefore, x = 58
Two friends compete with each other and five other, equally good, violinists for first and second chair in an orchestra, in a blind competition What is the probability that the two friends end up as first and second chair together?
Answer: 0.0476
Step-by-step explanation:
Given : Two friends and 5 other people compete with each other for first and second chair in an orchestra.
Total people in this competition= 2+5=7
By permutation , Number of ways to arrange 7 people= 7!
Also, number of ways for two friends end up as first and second chair together= 2 × 5! [ 2 ways to arrange friends on first and second chair and 5! ways to arrange others]
I.e. Required probability = [tex]\dfrac{2\times5!}{7!}[/tex]
[tex]=\dfrac{2!\times5!}{7\times6\times5!}\\\\=\dfrac{1}{7\times3}\\\\=\dfrac{1}{21}\\\\=0.0476[/tex]
Hence, the probability that the two friends end up as first and second chair together = 0.0476
What is the sum of the geometric sequence?
Answer:
B. 259
Step-by-step explanation:
6^(i - 1) for i = 1 to 4
sum = 6^(1 - 1) + 6^(2 - 1) + 6^(3 - 1) + 6^(4 - 1) =
= 6^0 + 6^1 + 6^2 + 6^3
= 1 + 6 + 36 + 216
= 259
Answer: B. 259
4. Katy has 6 times as many nickels as
Shaun. Shaun has 18 nickels. How many
nickels, n, does Katy have?
n is 6
18.
n=
Answer:
[tex]\huge\boxed{n = 108\ nickels}[/tex]
Step-by-step explanation:
Let the nickels with Katy be n
So, the condition is
n = 6 (Shaun nickels)
While Nickels of Shaun = 18 , So
n = 6 (18)
n = 108 nickels
At a store An orange costs 18 cents A pineapple costs 27 cents An apple costs 15 cents How much does a strawberry cost??
Answer:
A strawberry cost 30 cents
Step-by-step explanation:
Given:
Orange= 18 cents
Pineapple = 27 cents
Apple = 15 cents
Strawberry = ?
From the given:
Orange has 6 letters multiplied by 3
=6 * 3
=18 cents
Pineapple has 9 letters multiplied by 3
=9 * 3
=27 cents
Apple has 5 letters multiplied by 3
= 5 * 3
= 15 cents
Therefore, cost of the strawberry=
Strawberry has 10 letters. Multiply the 10 letters by 3
That is,
10 × 3
= 30 cents
Problem is attached in a photo
Answer:
y<(x-2)^2
Step-by-step explanation:
To graph this inequality, we first identify the function.
This is a quadratic function y=x^2
The function is translated horizontally to the right two. (x-2)^2
It is also a dotted line, <.
In this diagram, bac~edf. if the area of bac= 6 in.², what is the area of edf? PLZ HELP PLZ PLZ PLZ PLZ
Answer:
Area of ΔEDF = 2.7 in²
Step-by-step explanation:
It's given in the question,
ΔBAC ~ ΔEDF
In these similar triangles,
Scale factor of the sides = [tex]\frac{\text{Measure of one side of triangle BAC}}{\text{Measure of one side of triangle EDF}}[/tex]
[tex]=\frac{\text{BC}}{\text{EF}}[/tex]
[tex]=\frac{3}{2}[/tex]
Area scale factor = (Scale factor of the sides)²
[tex]\frac{\text{Area of triangle BAC}}{\text{Area of triangle EDF}}=(\frac{3}{2})^2[/tex]
[tex]\frac{6}{\text{Area of triangle EDF}}=(\frac{9}{4})[/tex]
Area of ΔEDF = [tex]\frac{6\times 4}{9}[/tex]
= 2.67
≈ 2.7 in²
Therefore, area of the ΔEDF is 2.7 in²
What is the sign of -456 +456
Answer:
0
Step-by-step explanation:
-456 +456
( - , + ) = -
so answer is 0
Answer:
0
Step-by-step explanation:
bc i know
Was it evaluated correctly?
Explain your reasoning
help i need to turn it in a hour
Answer:
no
Step-by-step explanation:
2(4+10)+20
2(14)+20
28+20
48
What is the median of these figure skating ratings?
6.0 6.0 7.0 7.0 7.0 8.0 9.0
Answer:
The median would be 7.0.
Step-by-step explanation:
The median of a set of numbers means it is the middle number. since this set has 7 numbers you would need to find the number that is in the middle of the set. This would be the 4th number since it is in the middle. 7.0 is your answer.
Credit card companies lose money on cardholders who fail to pay their minimum payments. They use a variety of methods to encourage their delinquent cardholders to pay their credit card balances, such as letters, phone calls and eventually the hiring of a collection agency. To justify the cost of using the collection agency, the agency must collect an average of at least $200 per customer. After a trial period during which the agency attempted to collect from a random sample of 100 delinquent cardholders, the 90% confidence interval on the mean collected amount was reported as ($190.25, $250.75). Given this, what recommendation(s) would you make to the credit card company about using the collection agency
Answer with explanation:
A x% confidence interval interprets that a person can be x% confident thatthe true mean lies in it.
Here, Credit card companies is using the collection agency to justify the cost of , the agency must collect an average of at least $200 per customer.
i.e. [tex]H_0:\mu \geq200,\ \ \ H_a:\mu<200[/tex]
The 90% confidence interval on the mean collected amount was reported as ($190.25, $250.75) .
I recommend that we can be 90% sure that the true mean collected amount lies in ($190.25, $250.75).
Also, $200 lies in it such that it is more far from $250.75 than $190.25, that means there are large chances of having an average is at least $200 per customer.
Find the value of the logarithm. log 122
Answer:
2.086
Step-by-step explanation:
Log 122 is equal to 2.086
I need help will rate you brainliest
Answer:
Yes you can
Step-by-step explanation:
To eliminate the denominator
Answer:
No
Step-by-step explanation:
We cannot be certain that x + 3 > 0
If it was negative then the sign of the inequality would change.
To solve find the critical values of the numerator/ denominator, that is
x = 2 and x = - 3
The domain is the split into 3 intervals
(- ∞, - 3 ), (- 3, 2), (2, + ∞ )
Use test points from each interval to determine valid solution
Question 18 i will maek the brainliest:)
Answer:
Median: 14.6, Q1: 6.1, Q3: 27.1, IR: 21, outliers: none
Step-by-step explanation:
Step 1: order the data from the least to the largest.
2.8, 3.9, 5.3, 6.1, 6.5, 7.1, 12.5, 14.6, 16.4, 16.4, 20.8, 27.1, 28.1, 30.9, 53.5
Step 2: find the median.
The median is the middle value, which is the 8th value in the data set.
2.8, 3.9, 5.3, 6.1, 6.5, 7.1, 12.5, [14.6,] 16.4, 16.4, 20.8, 27.1, 28.1, 30.9, 53.5
Median = 14.6
Step 2: Find Q1,
Q1 is the middle value of the lower part of the data set that is divided by the median to your left.
2.8, 3.9, 5.3, (6.1), 6.5, 7.1, 12.5, [14.6], 16.4, 16.4, 20.8, 27.1, 28.1, 30.9, 53.5
Q1 = 6.1
Step 3: find Q3.
Q3 is the middle value of the upper part of the given data set.
2.8, 3.9, 5.3, 6.1, 6.5, 7.1, 12.5, [14.6], 16.4, 16.4, 20.8, (27.1), 28.1, 30.9, 53.5
Q3 = 27.1
Step 4: find interquartile range (IR)
IR = Q3 - Q1 = [tex] 27.1 - 6.1 = 21 [/tex]
Step 5: check if there is any outlier.
Formula for checking for outlier = [tex] Q1 - 1.5*IR [/tex]
Then compare the result you get with the given values in the data set. Any value in the data set that is less than the result we get is considered an outlier.
Thus,
[tex] Q1 - 1.5*IR [/tex]
[tex]6.1 - 1.5*21 = -25.4[/tex]
There are no value in the given data set that is less than -25.4. Therefore, there is no outlier.
Find X using the Angle Sum Theorem
Answer:
Step-by-step explanation:
x + 30 + 25 = 180
x + 55 = 180
x = 125
y + 125 = 180
y = 55
one third multiplied by the sum of a and b
Answer:
1/3(a+b)
hope it helps :>
_______% of 44 = 22
Answer:
50%
Step-by-step explanation:
22 is half of 44.
So, this means 50% of 44 is 22.
