Answer:
D
Step-by-step explanation:
For example,
5×7-10>20
5(-3)-10<15
how many line of symmetry is this figure
Answer:
There are sixteen lines.
The battery standby duration (in hours) of a new model of cell phone is known to be normally distributed. Ten pieces of such new model of cell phone supplied from the manufacturer are randomly chosen and the actual standby durations are recorded as below:
48.2 47.8 45.6 47.2 49.3
51.2 44.2 45.4 49.2 43.6
(a) Calculate the unbiased estimates of population mean and standard deviation of battery standby duration (in hours) of the new cell phone.
(b) The manufacturer claimed that this new model of cell phone has the mean battery standby duration of longer than 46.5 hours. Test at 1% significance level if this claim is true.
x = number of hours
want to find probability (P) x >= 13
x is N(14,1) transform to N(0,1) using z = (x - mean) / standard deviation so can look up probability using standard normal probability table.
P(x >= 13) = P( z > (13 - 14)/1) = P(z > -1) = 1 - P(z < -1) = 1 - 0.1587 = 0.8413
To convert that to percentage, multiply 100, to get 84.13%
Using the proportion you found in Question 3, write an equation for the length of arc EF in terms of the radii of AB and AC and the length of arc CD.
Answer:
Step-by-step explanation:
The triangle below is equilateral. Find the length of side x in simplest radical form
with a rational denominator.
12
Answer:
4sqrt(3)
Step-by-step explanation:
If the triangle is equilateral, the hypotenuse is 2x
We can use the Pythagorean theorem
a^2 + b^2 = c^2 where a and b are the legs and c is the hypotenuse
x^2 + 12^2 = (2x)^2
x^2 + 144 = 4x^2
144 = 4x^2 -x^2
144 = 3x^2
48 = x^2
Taking the square root of each side
sqrt(48) = sqrt(x^2)
sqrt(16*3) = x
4 sqrt(3) =x
In a large midwestern university (the class of entering freshmen being on the order of 6000 or more students), an SRS of 100 entering freshmen in 1999 found that 20 finished in the bottom third of their high school class. Admission standards at the university were tightened in 1995. In 2001 an SRS of 100 entering freshmen found that 10 finished in the bottom third of their high school class. The proportion of all entering freshmen in 1999 and 2001, who graduated in the bottom third of their high school class, are p1 and p2, respectively.Is there evidence that the proportion of freshmen who graduated in the bottom third of their high school class in 2001 has been reduced, as a result of the tougher admission standards adopted in 2000, compared to the proportion in 1999? To determine this, you test the hypothesesH0 : p1 = p2 , Ha : p1 > p2.The P-value of your test isA. 0.976.B. 0.024.C. 0.048.D. 0.001.
Answer:
B. 0.024
The p-value of the test is 0.024 < 0.05(standard significance level), which means that there is enough evidence that the proportion of freshmen who graduated in the bottom third of their high school class in 2001 has been reduced.
Step-by-step explanation:
Before testing the hypothesis, 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.
1999:
Of 100, 20 were in the bottom thid. So
[tex]p_B = \frac{20}{100} = 0.2[/tex]
[tex]s_B = \sqrt{\frac{0.2*0.8}{100}} = 0.04[/tex]
2001:
Of 100, 10 were in the bottom third, so:
[tex]p_A = \frac{10}{100} = 0.1[/tex]
[tex]s_A = \sqrt{\frac{0.1*0.9}{100}} = 0.03[/tex]
To determine this, you test the hypotheses H0 : p1 = p2 , Ha : p1 > p2.
Can also be rewritten as:
[tex]H_0: p_B - p_A = 0[/tex]
[tex]H_1: p_B - p_A > 0[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{s}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error.
0 is tested at the null hypothesis:
This means that [tex]\mu = 0[/tex]
From the sample:
[tex]X = p_B - p_A = 0.2 - 0.1 = 0.1[/tex]
[tex]s_A = \sqrt{s_A^2+s_B^2} = \sqrt{0.03^2+0.04^2} = 0.05[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{s}[/tex]
[tex]z = \frac{0.1 - 0}{0.05}[/tex]
[tex]z = 2[/tex]
P-value of the test and decision:
The p-value of the test is the probability of finding a difference of proportions of at least 0.1, which is 1 subtracted by the p-value of z = 2.
Looking at the z-table, z = 2 has a p-value of 0.976.
1 - 0.976 = 0.024, so the p-value is given by option B.
The p-value of the test is 0.024 < 0.05(standard significance level), which means that there is enough evidence that the proportion of freshmen who graduated in the bottom third of their high school class in 2001 has been reduced.
helppppppppppppppppppp helppppppppppppp
HOPE ITS HELPFUL ^_^
•RHONA18) Mala gave Kamala half the number of sweets she had. She then had 7 sweets left. How many sweets did Mala have at the start?
Answer:
Mala had 14 sweets at the start.
Step-by-step explanation:
7 x 2 = 14
To check, 14/2 = 7. (Dividing by 2 is the same as multiplying by 1/2)
A bag of marbles contains 3 blue marbles, 2 green marbles and 5 red marbles. A marble is chosen at random. The probability that the marble selected is blue is:
Step-by-step explanation:
the probability will be amount of green marbles over total amount of marbles
if there are 2 green marbles, and 10 total the probability is 2/10, or 20%
What are the simplest forms for red, blue, and green line
Answer:
Red line: y=-1/2x+1 Blue line: y=-1/3x-2 Green line: y=x
Step-by-step explanation:
f(x) red line m=-1/2 b=1
g(x) blue line m=-1/3 b=-2
h(x) green line m=1 b=0
Graph the function need ASAP help
Is it a, b , c or d?
Answer:
D
Step-by-step explanation:
(the line is a / shape, so the slope is positive)
(the line crosses the y axis at (0,-2)
(using the above information, the equation is y=2x-2)
Answer:
y = 2x - 2
Step-by-step explanation:
Start with
y = mx + b
The graph shows the y-intercept -2.
We have y = mx - 2
slope = m = rise/run
The slope is rise of 2 and run of 1, so m = 2.
y = 2x - 2
A traveling salesman figures it costs 28
cents for every mile he drives his car. How much does it cost him (in dollars) a week to drive his car if he travels 315 miles a week?
A rancher’s herd of 250 sheep grazes over a 40-acre pasture. He would like to find out how many sheep are grazing on each acre of the pasture at any given time, so he has some images of the pasture taken by the state department of agriculture’s aerial photography division. Here are three samples of the images.
Sample 1 : 4
Sample 2 : 1
Sample 3 : 9
What margin of error is reasonable for these samples?
Answer:
Sample 1 MOE = 37.24%
Sample 2 MOE = 29.4%
Sample 3 MOE = None
Step-by-step explanation:
We are told that 250 sheep grazes over a 40-acre pasture.
Thus, number of sheeps per acre = 250/40 = 6.25 ≈ 6
Thus, n = 6
For the samples given, we can find sample proportions as;
Sample 1: p_o = 4/6 = 0.67
Sample 2: p_o = 1/6 = 0.17
Sample 3: p_o = 9/6 = 1.5
Formula for test statistic here is;
z = √(p_o(1 - p_o)/n)
For sample 1;
z = √(0.67(1 - 0.67)/6)
z ≈ 0.19
For sample 2;
z = √(0.17(1 - 0.17)/6)
z ≈ 0.15
For sample 3;
z = √(1.5(1 - 1.5)/6)
z = √−0.125
We are not given confidence level but we will use 95%.
Value of z_α at 95% Confidence level is 1.96. Thus, we can find the margin of error for the samples;
For sample 1;
Margin of error at z = 0.19 is;
1.96 × 0.19 = 0.3724 = 37.24%
For sample 2;
Margin of error at z = 0.15 is;
1.96 × 0.15 = 0.294 = 29.4%
For sample 3;
Since test statistic has a negative square root, then it has no margin of error.
Find the number in which 9 has greater value.
0.5689
5.6890
56.89
569.80
Answer:
569.80Step-by-step explanation:
Among all the choices, the digit 9 has the greatest value in number 569.80. For the reason that 9 got ones value - which are greatest than other.[tex]\tt{ \green{P} \orange{s} \red{y} \blue{x} \pink{c} \purple{h} \green{i} e}[/tex]
Use the diagram (click the image above) to find the measure of the segment or angle.
1. m
2. m
3. GH =
4. BC =
Answer:
Step-by-step explanation:
From the given angles ∠ABC and ∠GHK,
m∠ABC = m∠GHK [Given]
m∠ABC = m∠GHL + m∠KHL [Since, ∠GHL + ∠KHL = ∠GHK]
(6x + 2)° = (5x - 27)° + (3x + 1)°
6x + 2 = 8x - 26
8x - 6x = 28
2x = 28
x = 14
m(BC) = m(HK) [Given]
3z + 6 = 8z - 9
8z - 3z = 6 + 9
5z = 15
z = 3
m(AB) = m(GH)
5y - 8 = 3y
2y = 8
y = 4
m∠ABC = mGHK = (6x + 2)
= 6(14) + 2
= 86°
m(AB) = m(GH) = 3y
= 3(4)
= 12 units
m(BC) = m(HK) = (3z + 6)
= 3(3) + 6
= 15 units
m(∠KHL) = (3x + 1)°
= 3(14) + 1
= 43°
[tex]\sqrt\\x^{2} - 3\\[/tex]
Find the square root of 1764 by factorisation method
Answer:
42
Step-by-step explanation:
prime factorisation of 1764 = 2^2 × 3^2 × 7^2
hence,
√1764 = √(2^2 × 3^2 × 7^2) =2 x 3 x 7 = 42
Answer:
42
Step-by-step explanation:
1764 = 2 * 882
= 2 * 2 * 441
= 2 * 2 * 3 * 147
= 2 * 2 * 3 * 3 * 49
= 2 * 2 * 3 * 3 * 7 * 7
[tex]\sqrt{1764} = \sqrt{2*2*3*3*7*7} = 2*3*7 = 42[/tex]
PLS HELP
Choose the inequality that represents the following graph,
+
-4
-5
-3
- 2
-1
0
1
2
3
4
5
Choose 1 answers
ISO
IO
D
>O
Answer:
The option which represents the inequality is option D ; stated as x ≥ 0
Step-by-step explanation:
The marked or dotted position is 0 ; which represents the position of x, when graphing inequality statements, if the point IS SHADED, then it means GREATER THAN EQUAL TO.
Option A is incorrect, the inequality sign is not the same as the direction of the arrow.
Option B, says LESS THAN EQUAL TO, instead of GREATER THAN EQUAL TO
Option C SAYS GREATER THAN instead of GREATER THAN EQUAL TO.
Therefore, Option D is the correct expression which means x is GREATER THAN EQUAL TO.
Learn more : https://brainly.com/question/24065770
slove for inequality of -6> t-(-13)
Step-by-step explanation:
-6>t-(-13)
= -6>t+13
= -6-13>t
= -19>t
= t<-19
Answer:
t < - 19
Step-by-step explanation:
Given
- 6 > t - (- 13) , that is
- 6 > t + 13 ( subtract 13 from both sides )
- 19 > t , then
t < - 19
Miguel withdrew $20 per week from his bank account for 4 weeks. Which expression shows the charge in his account balance?
a. -20 + 4
b. -20 - 4
c. -20 • 4
d. -20 / 4
(I think it’s C)
Please help me, this is due for tomorrow!
Answer:
C
Step-by-step explanation:
You are correct
*Per something means multiplication*
20 per 4 weeks = 20 × 4
1 If f(x) = 1/2x + 14, then f ^-1(x)=
Answer:
2x-24
I think that you changes the problem...
you went from a derivative to an inverse ???
y = 1/2x + 14
x = 1/2 y + 14
2x = y + 24
y = 2x-24
Step-by-step explanation:
Answer:
[tex]f^{-1}[/tex] (x) = 2x - 28
Step-by-step explanation:
let y = f(x) and rearrange making x the subject
y = [tex]\frac{1}{2}[/tex] x + 14 ( multiply through by 2 to clear the fraction )
2y = x + 28 ( subtract 28 from both sides )
2y - 28 = x
Change y back into terms of x with x = [tex]f^{-1}[/tex] (x)
[tex]f^{-1}[/tex] (x) = 2x - 28
HELP ASAP PLEASE!!! 100 point!!!!!!!!!!
FOR THE GRAPHS JUST GIVE ME TWO POINTS FOR EACH ONE!!!!!!!!!!!!!!
Answer:
y=4x+7
Step-by-step explanation:
use the slope intercept formula to find the equation.
y =4
passess through (-1,3)
Which is the graph of f(x) = (2)* ?
Answer:
the graph of f(x)=×2 called a parabola
PLS HELP ME
The width of a rectangle is 20m to 2 significant figures
The length of a rectangle is 40m to 1 significant figure
What is the shortest perimeter the rectangle could have?
Answer:
80m
Step-by-step explanation:
(20x2) =40m + 40m= 80m
what is the correct expansion of this expression (w-p)(3p+w)
Answer:
3pw + w^2 - 3p^2 - pw = 2pw + w^2 - 3p^2
Step-by-step explanation:
Multiply every term of the first binomial by every term of the second binomial.
(w - p)(3p + w) = 3pw + w^2 - 3p^2 - pw = 2pw + w^2 - 3p^2
Answer for this question?
Answer:
B
Step-by-step explanation:
Lie should factor out 3 from the expression
Rectangle KLMN has vertices K(-5,6), L(-2,9), M(6, 1), and N(3,-2). Determine and state the coordinates of the point of intersection of the diagonals.
Answer:
(0.5,3.5)
Step-by-step explanation:
First, we can draw the image, as shown. The diagonals in the rectangle are the following lines:
from (-2,9) to (3,-2)
from (-5, 6) to (6,1)
To find where they intersect, we can start by making an equation for the lines. For an equation y=mx+b, m represents the slope and b represents the y intercept, or when x=0
For the first line, from (-2,9) to (3,-2), we can calculate the slope by calculating the change in y/change in x = (y₂-y₁)/(x₂-x₁). If (3,-2) is (x₂,y₂) and (-2,9) is (x₁,y₁), our slope is
(-2-9)/(3-(-2)) = -11/5
Therefore, our equation is
y= (-11/5)x + b
To solve for b, we can plug a point in, like (3,-2). Therefore,
-2=(-11/5)*3+b
-2=-33/5+b
-10/5=-33/5+b
add 33/5 to both sides to isolate b
23/5=b
Our equation for one diagonal is therefore y=(-11/5)x+23/5
For the second line, from (-5, 6) to (6,1), if (6,1) is (x₁,y₁) and (-5,6) is (x₂,y₂), the slope is (1-6)/(6-(-5)) = -5/11 . Plugging (6,1) into the equation y=(-5/11)x+b, we have
1=(-5/11)*6+b
11/11 = -30/11 + b
add 30/11 to both sides to isolate b
41/11 = b
our equation is
y = (-5/11) x + 41/11
Our two equations are thus
y = (-5/11) x + 41/11
y=(-11/5)x+23/5
To find where they intersect, we can set them equal to each other
(-11/5)x+23/5 = y = (-5/11) x + 41/11
(-11/5)x + 23/5 = (-5/11)x + 41/11
subtract 23/5 from both sides as well as add 5/11 to both sides to make one side have only x values and their coefficients
(-11/5)x + (5/11)x = 41/11-23/5
11*5 = 55, so 55 is one value we can use to make the denominators equal.
(-11*11/5*11)x+(5*5/11*5)x=(41*5/11*5)-(23*11/5*11)
(-121/55)x+(25/55)x = (205/55) - (253/55)
(-96/55)x = (-48/55)
multiply both sides by 55 to remove the denominators
-96x=-48
divide both sides by -96 to isolate x
x=-48/-96=0.5
plug x=0.5 into a diagonal to see the y value of the intersection
(-11/5)x + 23/5 = y = (-11/5)* 0.5 + 23/5 = 3.5
Can somebody help me please!!!!!
Answer:
0
Step-by-step explanation:
g[f(x)] = x^2 - 3
= 3x^2
if gf(0) = 3(0)^2
= 0
What is the approximate length of the line segment?
(1, -1)
(6,-8)
Answer:
8.6023
Step-by-step explanation:
length = √[(x2-x1)^2+(y2-y1)^2]
=√[(1-6)^2+(-1--8)^2] =√74 =8.6023
Given that squareroot 9.8 = 3.13 and squareroot 98 = 9.9 , then squareroot 98000=??
How they connected?
Answer:
see your answer in pic
mark me brainlist
Step-by-step explanation:
Find the equation of a line perpendicular to y = (75)x - 1 and has a y-
intercept of 1.
Answer:
6y = -5x + 6
y = -5/6 x + 1
Step-by-step explanation:
y = -5/6 x + b
1 = b
