Answer: S₁₉ = 855
Step-by-step explanation:
T₄ = a + ( n - 1 )d = 5 , from the statement above , but n = 4
a + 3d = 5 -------------------------1
S₆ = ⁿ/₂[(2a + ( n - 1 )d] = 10, where n = 6
= ⁶/₂( 2a + 5d ) = 10
= 3( 2a + 5d ) = 10
= 6a + 15d = 10 -----------------2
Now solve the two equation together simultaneously to get the values of a and d
a + 3d = 5
6a + 15d = 10
from 1,
a = 5 - 3d -------------------------------3
Now put (3) in equation 2 and open the brackets
6( 5 - 3d ) + 15d = 10
30 - 18d + 15d = 10
30 - 3d = 10
3d = 30 - 10
3d = 20
d = ²⁰/₃.
Now substitute for d to get a in equation 3
a = 5 - 3( ²⁰/₃)
a = 5 - 3 ₓ ²⁰/₃
= 5 - 20
a = -15.
Now to find the sum of the first 19 terms,
we use the formula
S₁₉ = ⁿ/₂( 2a + ( n - 1 )d )
= ¹⁹/₂( 2 x -15 + 18 x ²⁰/₃ )
= ¹⁹/₂( -30 + 6 x 20 )
= ¹⁹/₂( -30 + 120 )
= ¹⁹/₂( 90 )
= ¹⁹/₂ x 90
= 19 x 45
= 855
Therefore,
S₁₉ = 855
A researcher surveys middle-school students on their study habits. She finds that in a random sample of 28 middle-school students, the mean amount of time that they spend working on the computer each night is 2.4 hours with a standard deviation of 0.92 hours. She uses the sample statistics to compute a 95% confidence interval for the population mean - the the mean amount of time that all middle-school students spend working on the computer each night. What is the margin of error for this confidence interval
Answer:
The margin of error is [tex]E = 1.96 * \frac{ 0.92}{\sqrt{28 } }[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is [tex]n = 28[/tex]
The sample mean is [tex]\= x = 2.4 \ hr[/tex]
The standard deviation is [tex]\sigma = 0.92 \ hr[/tex]
Given that the confidence level is 95% the the level of significance can be evaluated as
[tex]\alpha = 100 -95[/tex]
[tex]\alpha = 5 \%[/tex]
[tex]\alpha = 0.05[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table,the value is [tex]Z_{\frac{\alpha }{2} } = Z_{\frac{0.05}{2} } = 1.96[/tex]
Generally the margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }[/tex]
substituting values
[tex]E = 1.96 * \frac{ 0.92}{\sqrt{28 } }[/tex]
[tex]E = 0.3408[/tex]
Plzzz help me on this question
This is Additional mathematics IGCSE
Answer:
[tex] \alpha = 7[/tex]
Step-by-step explanation:
[tex]a(vector) = 4i - 2j[/tex]
[tex]b(vector) = \alpha i + 2j[/tex]
[tex]ab(vector) = ( \alpha - 4)i \: + 4j[/tex]
Now,
Let K * ab (unit vector) = ab (vector)
(0.4 * k) j = 4 j Thus, K = 10[tex](0.3 \times k)i = ( \alpha - 4)i[/tex]Solving further :
[tex] \alpha = 7[/tex]
Use a definition, postulate, or theorem to find the value of x in the figure described. Point E is between points D and F. If DE = x − 3, EF = 6x + 5, and DF = 8x − 3, find x. Select each definition, postulate, or theorem you will use. A)definition of segment bisector B)definition of midpoint C)Linear Pair Theorem D)Segment Addition Postulate The solution is x =?
Answer:
Option (D)
x = 5
Step-by-step explanation:
Since point E is in the mid of the segment DF,
Therefore, by the Segment addition postulate,
DF = DE + EF
Since DF = (8x - 3), DE = (x - 3) and EF = (6x + 5)
By substituting these values in the given postulate,
(8x - 3) = (x - 3) + (6x + 5)
8x - 3 = (x + 6x) + (5 - 3)
8x - 3 = 7x + 2
8x - 7x = 3 + 2
x = 5
Therefore, x = 5 will be the answer.
Answer:
x=6 and D
Step-by-step explanation:
In 2004, 50 out of every 100 drivers at the National Trucking Company passed their driver's license exam on their first try. In 2005, 62 of the drivers passed on their first attempt. What was the percent increase in the passing rate?
Answer:
I believe it's a 12 percent increase.
Step-by-step explanation:
50/100= 50%
62/100= 62%
62%-50%=12%
Sketch the graph of the following equations:
y-3x+5
y=-3x-5
Which expression is equivalent to 5y^3/(5y)^-2
Answer:
5^3 y^5
125 y^5
Step-by-step explanation:
5y^3/(5y)^-2
Distribute the exponent in the denominator
5y^3/(5 ^-2 y^-2)
A negative exponent in the denominator brings it to the numerator
5y^3 5 ^2 y^2
Combine like terms
5 * 5^2 * y^3 5^2
We know that a^b * a^c = a^(b+c)
5^(1+2) * y^( 3+2)
5^3 y^5
125 y^5
In a triangle, the sum of two angles equals the third, Find the measure of the third angle.
A.45 degree
B.60 degree
C.90 degree
D.30 degree
Answer:
C.90 degree
Step-by-step explanation:
45 + 45 + 90 = 180
90 = 45 + 45
Allied Corporation is trying to sell its new machines to Ajax. Allied claims that the machine will pay for itself since the time it takes to produce the product using the new machine is significantly less than the production time using the old machine. To test the claim, independent random samples were taken from both machines. You are given the following results.
New Machine Old Machine
Sample Mean 25 23
Sample Variance 27 7.56
Sample Size 45 36
As the statistical advisor to Ajax, would you recommend purchasing Allied's machine? Explain.
Answer:
z(s) is in the acceptance region. We accept H₀ we did not find a significantly difference in the performance of the two machines therefore we suggest not to buy a new machine
Step-by-step explanation:
We must evaluate the differences of the means of the two machines, to do so, we will assume a CI of 95%, and as the interest is to find out if the new machine has better performance ( machine has a bigger efficiency or the new machine produces more units per unit of time than the old one) the test will be a one tail-test (to the left).
New machine
Sample mean x₁ = 25
Sample variance s₁ = 27
Sample size n₁ = 45
Old machine
Sample mean x₂ = 23
Sample variance s₂ = 7,56
Sample size n₂ = 36
Test Hypothesis:
Null hypothesis H₀ x₂ - x₁ = d = 0
Alternative hypothesis Hₐ x₂ - x₁ < 0
CI = 90 % ⇒ α = 10 % α = 0,1 z(c) = - 1,28
To calculate z(s)
z(s) = ( x₂ - x₁ ) / √s₁² / n₁ + s₂² / n₂
s₁ = 27 ⇒ s₁² = 729
n₁ = 45 ⇒ s₁² / n₁ = 16,2
s₂ = 7,56 ⇒ s₂² = 57,15
n₂ = 36 ⇒ s₂² / n₂ = 1,5876
√s₁² / n₁ + s₂² / n₂ = √ 16,2 + 1.5876 = 4,2175
z(s) = (23 - 25 )/4,2175
z(s) = - 0,4742
Comparing z(s) and z(c)
|z(s)| < | z(c)|
z(s) is in the acceptance region. We accept H₀ we did not find a significantly difference in the performance of the two machines therefore we suggest not to buy a new machine
The very hight dispersion of values s₁ = 27 is evidence of frecuent values quite far from the mean
=
Graphing an integer function and finding its range for a given...
The function h is defined as follows for the domain given.
h(x) = 2 -2x, domain = {-3, -2, 1, 5}
Write the range of h using set notation. Then graph h.
Answer:
Step-by-step explanation:
● h(x) = 2-2x
The domain is {-3,-2,1,5}
● h(-3) = 2-2×(-3) = 2+6 = 8
● h(-2) = 2 -2×(-2) = 2+4 = 6
● h(1) = 2-2×1 = 2-2 = 0
● h(5) = 2-2×5 = 2-10 = -8
The range is {-8,0,6,8}
Find the value of x.
A. 22
B. 7.3
C. 3.6
D. 5.5
Answer:
x= 5.5
Step-by-step explanation:
(segment piece) x (segment piece) = (segment piece) x (segment piece)
x*4 = 11*2
4x = 22
Divide each side by 4
4x/4 = 22/4
x =5.5
there are 5 discs, 6 jump ropes, 3 balls, and 12 pieces of sidewalk chalk in a bin. If two items are drawn at random without replacement, what is the probability that both items removed are not jump ropes?
Answer: 0.584
Step-by-step explanation:
We have:
5 discs
6 jump ropes
3 balls
12 pieces of sidewalk.
5 + 6 + 3 + 12 = 26
If all of them have exactly the same probability of being removed, then:
in the first selection, we do not want to remove a jump rope, so we can remove one disc, one ball or one piece of sidewalk.
The total number of those objects is:
5 + 3 + 12 = 20.
Then the probability of removing one of those objects is:
P1 = 20/26 = 0.769
Now in the second selection, we have the same situation, but now we have 25 objects in total, and because in the previous selection we removed one ball, or one disc, or one piece of sidewalk, the total number of these things now is 19.
So the probability of removing another object of that set is:
P2 = 19/25 = 0.76
The joint probability is equal to the product of the individual probabilities, so we have:
P = P1*P2 = 0.769*0.76 = 0.584
Can someone please help I don't understand. Determine the domain and range of the following function. Record your answers in set notation.
Look at the screenshot!!!
Let A= {1 , 2 , 3 , ... ... ...... , 10} and R = {(a, b): a ∈ A , b ∈ A and a + 2b = 10} Find the domain and range of R.
In domain and range of a relation, if R be a relation from set A to set B, then
• The set of all first components of the ordered pairs belonging to R is called the domain of R.
Thus, Dom(R) = {a ∈ A: (a, b) ∈ R for some b ∈ B}.
• The set of all second components of the ordered pairs belonging to R is called the range of R.
Thus, range of R = {b ∈ B: (a, b) ∈R for some a ∈ A}.
Therefore, Domain (R) = {a : (a, b) ∈ R} and Range (R) = {b : (a, b) ∈ R}
Five more than the square of a number Five more than twice a number Five less than the product of 3 and a number Five less the product of 3 and a number Twice the sum of a number and 5 The sum of twice a number and 5 The product of the cube of a number and 5 The cube of the product of 5 and a number. 5 + x2 5 + 2x 5 - 3x 3x - 5 2x + 5 2(x + 5) 5x3 (5x)3 WILL MARK BRAINLIEST AND DON'T PUT A FAKE ANSWER TO GET POINTS EITHER CUS I NEED HELP
Answer:
BelowStep-by-step explanation: Let all unknown no be x
Five more than the square of a number
= [tex]5 + x^2[/tex]
Five more than twice a number ;
[tex]5+2x\\= 2x+5[/tex]
Five less than the product of 3 and a number ;
[tex]5- 3x\\= 3x-5[/tex]
Twice the sum of a number and 5 ;
[tex]2(x+5)\\[/tex]
The sum of twice a number and 5 ;
[tex]2x+5[/tex]
The product of the cube of a number and 5;
[tex]x^3 \times 5\\=5x^3[/tex]
The cube of the product of 5 and a number ;
[tex](5\times x)^3\\(5x)^3[/tex]
PLEASE HELP! (1/4) - 50 POINTS -
Answer:
D) 0.35
Step-by-step explanation:
The table gives the area between z=0 and the given magnitude of z. That is, the area between z = 0 and z = -0.6 is 0.23, as found in the 0.6 column of the table. Similarly, the area between z = 0 and z = 0.3 is 0.12, as found in the 0.3 column of the table.
The area between z = -0.6 and z = +0.3 is the sum of these areas:
p(-.6<z<.3) = 0.23 +0.12 = 0.35
please help. urgent. calculate the value of: E= x^3+1/x^3 if 1/x+x=4
(picture below)
Answer:
52
Step-by-step explanation:
1. We see if we cube both sides of the second equation, then it looks more similar to the first equation (E = x^3 + 1/x^3)
(1/x + x)^3 = 4^3
1/x^3 + 3/x + 3x + x^3 = 64
2. Now we rearrange, because we see x^3 + 1/x^3 in the first equation in this equation
x^3 + 1/x^3 + 3x + 3/x = 64
3. We look at 3x + 3/x and see that it looks like the second equation, so we try factoring it
x^3 + 1/x^3 + 3(x + 1/x) = 64
we know x + 1/x = 4, so 3(x + 1/x) = 12
x^3 + 1/x^3 +12 = 64
4. Now we subtract and get our answer
x^3 + 1/x^3 = 52
Please answer this correctly without making mistakes
Answer:
105/4 or 26.25 mi
Step-by-step explanation:
hillsdale to fairfax 8 7/8 = 71/8
fairfax to yardley = 17 3/8 = 139/8
71/8 + 139/8 = 105/4 or 26 2/8
HELP PLEASE PLEASE :(
Answer:
16
Step-by-step explanation:
It’s a ratio.
x/12=21/28
21x=12*28
21x=336
x=336/21
x=16
Based on the image, which list of 3 points are collinear?
Answer:
Collinear occurs when the two points has the same gradient,
So, for this question any line that forms by any three points would be collinear.
Hence, EBF,DGC,MGN,BGA are all collinears
Step-by-step explanation:
BRAINLIEST ANSWER GIVEN! Find the equation of the line passing through the pair points (-8,6) (-9,-9). The equation of the line in the form is Ax+By=C.
Answer:
y=15x+126
Step-by-step explanation:
the slope is
15 because -8-(-9) is 1 and 6-(-9) is 15 and y is over x so slope 15
To find y intercept start from -8,6 and add 15 to the y value every time you add one to the x value
you will add 8 times and you get 126 as the intercept
Find the intersection point for the following liner function f(x)= 2x+3 g(x)=-4x-27
Answer:
( -5,-7)
Step-by-step explanation:
f(x)= 2x+3 g(x)=-4x-27
Set the two functions equal
2x+3 = -4x-27
Add 4x to each side
2x+3+4x = -4x-27+4x
6x+3 = -27
Subtract 3
6x+3 - 3 = -27-3
6x = -30
Divide each side by 6
6x/6 = -30/6
x =-5
Now we need to find the output
f(-5) = 2(-5) +3 = -10+3 = -7
Answer:
Step-by-step explanation:
big burgewr
Write down the answers to a,b,c,d
Answer:
(A) 1
(B) -2
(C) 3.5
(D) -0.5
Step-by-step explanation:
We can treat each thermometer like a vertical number line and read the values on each.
A is right on 1.
B is right on -2.
C is in the middle of 3 and 4, so 3.5
D is in the middle of 0 and -1, so -0.5
Hope this helped!
The table shows data collected on the relationship between time spent playing video games and time spent with family. The line of best fit for the data is ý = -0.363 +94.5. Assume the line of best fit is significant and there is a strong linear relationship between the variables.
Video Games (Minutes) Time with Family (Minutes)
40 80
55 75
70 69
85 64
Required:
a. According to the line of best fit, what would be the predicted number of minutes spent with family for someone who spent 36 minutes playing video games?
b. The predicted number of minutes spent with family is:_________
Answer:
81.432 minutes
Step-by-step explanation:
Given the following :
Video Games (Mins) - - - Time with Family(Mins)
40 - - - - - - - - - - - - - - - - - - - 80
55 - - - - - - - - - - - - - - - - - - - 75
70 - - - - - - - - - - - - - - - - - - - 69
85 - - - - - - - - - - - - - - - - - - - 64
Best fit line:
ý = -0.363x +94.5
For someone who spent 36 minutes playing video games, the predicted number of minutes spent with family according to the best fit line will be:
Here number of minutes playing video games '36' is the independent variable
ý is the dependent or predicted variable ;
94.5 is the intercept
ý = -0.363(36) +94.5
ý = −13.068 + 94.5
ý = 81.432 minutes
Which is about 81 minutes to the nearest whole number.
How do i do this equation
-3(-2y-4)-5y-2=
Answer:
combined like terms and then follow the order of operations.
Step-by-step explanation:
In a large on-the-job training program, half of the participants are female and half are male. In a random sample of six participants, what is the probability that an investigator will draw at least one male?† (Round your answer to four decimal places.) P(X ≥ 1) =
Answer: 0.9844
Step-by-step explanation:
given data:
sample size n = 6
It’s assumed that half the population are male and the remaining half are females
F = 1/2
M = 1/2
the probability that the investigator would draw altleats one male
P ( x ≥ 1 ) =
= 1 - ( 0.5 ) ^ 6
= ( 0.5 )^6
= 0.9844
PLEASE it's easy - "collecting like terms" It's algebra
Answer: The equation is correct.
Step-by-step explanation:
from the expression,
5x + 3( y + 4x² + 3x ) + 2( y - x² ) = 14x + 10x² + 5y
Open brackets with 3 and 2
5x + 3y + 12x² + 9x + 2y - 2x²
Now collect like terms
5x + 9x + 12x² - 2x² + 3y + 2y
14x + 10x² + 5y = 14x + 10x² + 5y (Q.E.D)
TH equation is correct
State whether each ratio forms a proportion.
1) 6:3, 18:9 2) 3:4, 30:40 3) 14/18,28/36 4) 2/5,5/2
Answer: Please Give Me Brainliest, Thank You!
#1, #2, #3 do, but #4 doesn't
Step-by-step explanation:
#1
18/9=2
6/3=2
#2
30/3=10
40/4=10
#3
28/14=2
36/18=2
Please help me with this ,
Answer:
(a) -2.3°/min
(b) -2.9°/min
Step-by-step explanation:
The average rate of change is the ratio of the difference in R values to the difference in the corresponding t values.
(a) m = (157.6 -226.6)/(30 -0) = -69/30 = -2.3 . . . degrees per minute
__
(b) m = (61.6 -119.6)/(70 -50) = -58/20 = -2.9 . . . degrees per minute
Suppose that 200 students are randomly selected from a local college campus to investigate the use of cell phones in classrooms. When asked if they are allowed to use cell phones in at least one of their classes, 40% of students responded yes. Using these results, with 95% confidence, the margin of error is 0.068. How would the margin of error change if the sample size increased from 200 to 400 students?
Answer:
It would change to 0.04802
Step-by-step explanation:
from this question we have that n became 400
40% of 400
= 160
p* = 160/400
= 0.4
1 - p* =
= 1 - 0.4
= 0.6
at confidence level,
1 - 0.95
= 0.05
alpha/2 = 0.025
z= 1.96
margin of error. E
= 1.96 x √[(0.4 x 0.6)/400]
= 1.96 x 0.0245
= 0.04802
M.E = 0.04802
A human factor expert recommends that there be atleast 9 square ft of floor space in a classroom for every student in the class. Find the min space required for 49 students
