Answer:
About 99.7% of births would be expected to occur within 51 days of the mean pregnancy length
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Standard deviation = 17.
About what percentage of births would be expected to occur within 51 days of the mean pregnancy length?
51/17 = 3.
So, within 3 standard deviations of the mean.
About 99.7% of births would be expected to occur within 51 days of the mean pregnancy length
On the first day of school, each student is given $0.50 to attend. On day two, each student earns $1.00. on day 3, $2.00, etc. How much do students earn on the 9th day
Answer:
255.50
Step-by-step explanation:
If each day the number is doubled, then all you must do is keep on doubling to the ninth day and then add it all together
When you cough,the radius of your trachea (windpipe) decreases,affecting the speed S of the air in the trachea. If r0 is the normal radius of the trachea, the relationship between the speed S of the air and the radius r of the trachea during a cough is given by a function of the form
S(r) = (r0 - r) ar^2
where a is positive constant. Find the radius r for which the speed of the air is greatest.
Answer: 2r(0)/3.
Step-by-step explanation:
So, we are given one Important data or o or parameter in the question above and that is the function of the form which is given below(that is);
S(r) = (r0 - r) ar^2 -----------------------------(1).
We will now have to differentiate S(r) with respect to r, so, check below for the differentiation:
dS/dr = 2ar (r0 - r ) + ar^2 (-1 ) ---------;(2).
dS/dr = 2ar(r0) - 2ar^2 - ar^2.
dS/dr = - 3ar^2 + 2ar(r0) ------------------(3).
Note that dS/dr = 0.
Hence, - 3ar^2 + 2ar(r0) = 0.
Making ra the subject of the formula we have;
ra[ - 3r + 2r(0) ] = 0. -------------------------(4).
Hence, r = 0 and r = 2r(0) / 3.
If we take the second derivative of S(r) too, we will have;
d^2S/dr = -6ar + 2ar(0). -------------------(5).
+ 2ar(0) > 0 for r = 0; and r = 2r(0)/3 which is the greatest.
Answer:
[tex]r =\frac{2r_{0}}{3}[/tex]
Step-by-step explanation:
We need to take the derivative of S(r) and equal to zero to maximize the function. In this conditions we will find the radius r for which the speed of the air is greatest.
Let's take the derivative:
[tex]\frac{dS}{dr}=a(2r(r_{0}-r)+r^{2}(-1))[/tex]
[tex]\frac{dS}{dr}=a(2r*r_{0}-2r^{2}-r^{2})[/tex]
[tex]\frac{dS}{dr}=a(2r*r_{0}-3r^{2})[/tex]
[tex]\frac{dS}{dr}=ar(2r_{0}-3r)[/tex]
Let's equal it to zero, to maximize S.
[tex]0=ar(2r_{0}-3r)[/tex]
We will have two solutions:
[tex]r = 0[/tex]
[tex]r =\frac{2r_{0}}{3}[/tex]
Therefore the value of r for which the speed of the air is greatest is [tex]r =\frac{2r_{0}}{3}[/tex].
I hope it helps you!
Complete A and B for 5-8 points.
Answer:
a) 4 hours
b) 11 am
Step-by-step explanation:
So say the number of hours is x
a) 72 + 6x = 96
6x = 24
x = 4
b) 7am + 4 hours = 11am
Which types of triangles can be formed by taking the cross-section of a rectangular prism like the one shown above?
Answer: Equilateral, isosceles and scalene.
Step-by-step explanation:
Factorise 2y^2 + y + 6xy + 9x - 3
Answer: (2y+3)(3x+y-1)
Step-by-step explanation:
First regroup the terms.
6xy+9x+2y^2+y-3
Second factor 3x out of 6xy+9x
3x(2y)+9x+2y^2+y-3
3x(2y)+3x(3)+2y^2+y-3
And you get
3x(2y+3)+2y^2+y-3
Third factor by grouping
Giving brainliest to CORRECT answer.
Answer:
D
If you put the equation into a calculator, it will show a graph of it.
When plotting points on the coordinate plane below, which point would lie on the y-axis?
(0, 1)
(7, 0)
(6, 8)
(8, 2)
Answer:
(0,1)
Step-by-step explanation:
i got it right
Write the expanded form of h(3k-12.4)
Answer:3hk - 12.4h
Step-by-step explanation:
h(3k-12.4)
h x 3k - h x 12.4
3hk - 12.4h
Solve |6k + 12| + 9=9 for k
Answer:
k= -2
Step-by-step explanation:
Harris Interactive® conducted a poll of American adults in August of 2011 to study the use of online medical information. Of the 1,019 randomly chosen adults, 60% had used the Internet within the past month to obtain medical information. Use the results of this survey to create an approximate 95% confidence interval estimate for the percentage of all American adults who have used the Internet to obtain medical information in the past month.
Answer:
[tex]0.60 - 1.96\sqrt{\frac{0.60(1-0.60)}{1019}}=0.570[/tex]
[tex]0.60 + 1.96\sqrt{\frac{0.60(1-0.60)}{1019}}=0.630[/tex]
The 95% confidence interval for the true proportion would be given by (0.570;0.630) .
And if we convert this into % we got (57.0%, 63.0%)
Step-by-step explanation:
The information given we have the following info given:
[tex] n = 1019[/tex] represent the sampel size
[tex] \hat p=0.6[/tex] represent the sample proportion of interest
The confidence level is 95%, our significance level would be given by [tex]\alpha=1-0.95=0.05[/tex] and [tex]\alpha/2 =0.025[/tex]. And the critical value would be given by:
[tex]z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96[/tex]
The confidence interval for the mean is given by the following formula:
[tex]\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}[/tex]
Replacing the info given we got:
[tex]0.60 - 1.96\sqrt{\frac{0.60(1-0.60)}{1019}}=0.570[/tex]
[tex]0.60 + 1.96\sqrt{\frac{0.60(1-0.60)}{1019}}=0.630[/tex]
The 95% confidence interval for the true proportion would be given by (0.570;0.630) .
And if we convert this into % we got (57.0%, 63.0%)
How to find the area of the seating area
Parallelogram area is base times height. Base of 14, height of 10,
Answer: A = (14 ft)(10 ft) second choice
Answer:
choice B
Step-by-step explanation:
Round 0.378 to the place underlined digit 3
Answer:
0.38
Step-by-step explanation:
7 is the 3rd digit, so 8 is greater then 5, so you round up, if it is correct, can you give brainiest
Answer:
0.40
Step-by-step explanation:
this is because the number before it is up to five and even more than 5 so we round it up by adding one to the next number and the remaining digit to zero
Ana has a rectangular garden with a width of 2.3 meters and a length of 2.8 meters. She makes the model below to help her determine the area of her garden. What is the area of Ana's garden?
Answer:
6.44 m2
Step-by-step explanation:
Look at recent question
Answer:
ok was it college math if so the I don't know
What is volume of a cylinder with base area 64pi cm² and a height equal to twice the radius? Give your answer in terms of pi.
512 pi
256 pi
1024 pi
4096 pi
Answer:
1024 pi
Step-by-step explanation:
The area formula is ...
A = πr^2
So, the radius is ...
r = √(A/π)
For the given area, the radius of the cylinder is ...
r = √(64π/π) = 8 . . . . cm
The height is said to be twice this value, so is 16 cm.
__
The volume of the cylinder is found from ...
V = Bh
where B is the base area and h is the height. Our cylinder has a volume of ...
V = (64π cm^2)(16 cm) = 1024π cm^3
B(4,8) and C(8,0) are the endpoints of a line segment. What is the midpoint M of that line
segment?
Write the coordinates as decimals or integers.
Answer:
(6,4)
Step-by-step explanation:
I just did quick math in my head.
Find the radius of Circle M, if the area of a sector is 36.07 cm^2 and the central angle of that sector is 58º. Round your answers to the hundredths place if necessary
Answer:
r = 5.97 cm
Step-by-step explanation:
The area of the sector is given by the following equation:
[tex]A = r*S = 2\pi*r^{2}*\frac{58}{360}[/tex]
Where:
r: is the radius
A: is the area
The radius is:
[tex]r = \sqrt{\frac{A}{2*\pi*58/360}} = \sqrt{\frac{36.07 cm^{2}}{2*\pi*58/360}} = 5.97 cm[/tex]
Therefore, the radius of Circle M is 5.97 cm.
I hope it helps you!
Find the area of the shaded region and choose the appropriate result?
Answer:
Option B
Step-by-step explanation:
The figures are made out of squares.
[tex]\text {Formula for area of a square: } A =s^2\\s-\text {Length of side.}[/tex]
Square 1 (the gray square):
The side measure is 4 cm.
[tex]A = 4^2 = 16cm^2[/tex]
Square 2 (white square):
The side measure is 2 cm.
[tex]A=2^2=4cm^2[/tex]
Subtract the area of the white square from the gray square to get the area of the shaded region:
[tex]16 - 4 =12[/tex]
The shaded region is [tex]12cm^2[/tex].
Option B should be the correct answer.
Brainilest Appreciated!
Which goes with which
Express this number in scientific notation 0.0008235
Solve for I.
3x -8 < 23 AND
- 4x + 26 > 6
brainliest quick!
Aiden wanted to model -15 + 15 = 0 on the number line. He first drew an arrow 15 units long starting from zero that pointed to the left. He then draws another arrow 15 units long starting from zero that points to the right. What error did Aiden make?
A. The first arrow he drew should have pointed to the right to represent -15.
B. The second arrow he drew should have pointed to the left to represent 15.
C. The first arrow he drew should have started at -15 instead of 0.
D. The second arrow he drew should have started at -15 instead of 0.
Answer:
c
Step-by-step explanation:
Answer:
it's D
Step-by-step explanation:
The number never goes over 0 so there is no need to put anything above 0
x^2 = 8x - 15
.......................
Answer: x= 5
Step-by-step explanation: Lets solve by completing the square.
You first need to get -15 by itself.
x^2-8x=15 Now you need to complete the square my finding a perfect constant that will go with x^2-8x, then add it to the other side containing -15 to balance the equation out.
-8x/2= -4^2=16 This will be the perfect square.
x^2-8x+16 = -15 + 16
(x-4)^2 = 1 factor into a binomial, then use the square root on both sides.
√ x-4 ^ 2 = √ 1
x-4 = 1
x=5
Please help ASAP! Will give BRAINLIEST! Please read the question THEN answer correctly! No guessing.
A 6-sided die is rolled three times. What is the probability of rolling a 4 each time?
A 0.00463
B. 0.99537
C 0.16667
D. 0.00231
Answer:
a
Step-by-step explanation:
math
what is (4 to the square root of 81)5?
Answer:
1310720
Step-by-step explanation:
Find out the frist part "4 to the square root of 81" 262144
then times it by 5
to get 1310720
Which of the following statements is FALSE? The correlation coefficient equals the proportion of data points that lie on a straight line. The correlation coefficient will be +1.0 only if all the data lie on an upward-tilting straight line. The correlation coefficient is undefined if all the data lie on a perfectly horizontal straight line. The correlation coefficient is a unitless number and must always lie between –1.0 and +1.0, inclusive.
Answer:
The first one is False.
Step-by-step explanation:
If the correlation coefficient can also be -1 if the data lies on an upward tilting straight line.
Solve for a given 2e^a =4b
Answer:
a = ln (2b)
Step-by-step explanation:
2e^a =4b
Divide each side by 2
2/2 e^a =4/2b
e^a = 2b
Take the natural log of each side
ln(e^a) = ln(2b)
a = ln (2b)
Solve for x - y = -3
Answer:
0-3=-3
Step-by-step explanation:
A circle with circumference 8 has an arc with a 288 central angle what is the length of the arc
Answer:3.3
Step-by-step explanation:
Circumference=8
Φ=288
π=3.14
Radius=r
Circumference=2 x π x r
8=2 x 3.14 x r
8=6.28 x r
Divide both sides by 6.28
8/6.28=(6.28 x r) /6.28
1.3=r
r=1.3
Length of arc =Φ/360 x 2 x π x r
Length of arc =288/360 x 3.14 x 1.3
Length of arc =0.8 x 3.14 x 1.3
Length of arc =3.3
Answer:32/5
Step-by-step explanation: did it in khan
