Automobile racing, high-performance driving schools, and driver education programs run by automobile clubs continue to grow in popularity. All these activities require the participant to wear a helmet that is certified by the Snell Memorial Foundation, a not-for-profit organization dedicated to research, education, testing, and development of helmet safety standards. Snell "SA" (Sports Application)-rated professional helmets are designed for auto racing and provide extreme impact resistance and high fire protection. One of the key factors in selecting a helmet is weight, since lower weight helmets tend to place less stress on the neck. The following data show the weight and price for 18 SA helmets.
W p
64 252
64 283
64 190
64 197
58 291
47 702
49 907
59 341
66 202
58 305
58 477
52 477
63 379
62 377
54 563
63 255
63 286
a. Develop a scatter diagram with weight as the independent variable.
b. Does there appear to be any relationship between these two variables?
There appears to be a - Select your answer -negativepositiveItem 2 linear relationship between the two variables. The heavier helmets tend to be less expensive.
c. Develop the estimated regression equation that could be used to predict the price given the weight.
The regression equation is (to 1 decimal and enter negative values as negative numbers). If your answer is zero enter "0".
Answers
Answer:
Step-by-step explanation:
Hello!
Given the variables
X₁: Weight of a safety helmet for racers
X₂: Price of a safety helmet for racers
Note, there is n= 17 observed values for each variable so for all calculations I'll use this number and disregard the 18 mentioned in the text.
a) Scatterplot in attachment.
b) If you look at the diagram it seems that there is a negative linear regression between the price and the weight of the helmets, meaning, the higher the helmet weights, the less it costs.
c) The estimated regression equation is ^Yi= a + bXi
n= 17; ∑Y= 6466; ∑Y²= 3063392; ∑X= 1008; ∑X²= 60294; ∑XY= 367536
Y[bar]= 380.35; X[bar]= 59.29
[tex]b= \frac{sumXY-\frac{(sumX)(sumY)}{n} }{sumX^2-\frac{(sumX)^2}{n} } = \frac{367536-\frac{1008*6466}{17} }{60294-\frac{(1008)^2}{17} } = -30.18[/tex]
[tex]a= Y[bar]- bX[bar]= 380.35-(-30.18)*59.29= 2169.77[/tex]
The estimated regression equation for the price of the helmets as a function of their weight is:
^Yi= 2169.77 -30.18Xi
I hope it helps!
Related Questions
The lengths of pregnancies are normally distributed with a mean of 250 days and a standard deviation of 15 days.
a. Find the probability of a pregnancy lasting 308 days or longer?
b. If we stipulate that a baby is premature if the length of the pregnancy is in the lowest 8% (8th percentile), find the length that separates premature babies from those who are not premature.
Answers
Answer:
a) 0.005% probability of a pregnancy lasting 308 days or longer
b) The pregnancy length that separates premature babies from those who are not premature is 229 days.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
[tex]\mu = 250, \sigma = 15[/tex]
a. Find the probability of a pregnancy lasting 308 days or longer?
This is 1 subtracted by the pvalue of Z when X = 308. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{308 - 250}{15}[/tex]
[tex]Z = 3.87[/tex]
[tex]Z = 3.87[/tex] has a pvalue of 0.99995
1 - 0.99995 - 0.00005
0.005% probability of a pregnancy lasting 308 days or longer
b. If we stipulate that a baby is premature if the length of the pregnancy is in the lowest 8% (8th percentile), find the length that separates premature babies from those who are not premature.
The 8th percentile is X when Z has a pvalue of 0.08. So it is X when Z = -1.405.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]-1.405 = \frac{X - 250}{15}[/tex]
[tex]X - 250 = -1.405*15[/tex]
[tex]X = -1.405*15 + 250[/tex]
[tex]X = 229[/tex]
The pregnancy length that separates premature babies from those who are not premature is 229 days.
where is the point (0, –4) located
Answers
4 points below the origin
What is the median for the given set of data?
[40, 54, 22, 30, 55, 13, 33}
A)
32
B)
33
C)
40
D)
42
Answers
13 22 30 33 40 54 55
x^2 = 8x - 15
.......................
Answers
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
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.
Answers
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!
Solve for I.
3x -8 < 23 AND
- 4x + 26 > 6
Answers
3x < 31
x = 31/3
-4x + 26 > 6
-4x > -20
x < 5
Determine the range of the following function {(-1,4)(0,6)(7,8)(2,-5)}
A) {-1,4,0,6}
B) {-1,0,7,8}
C) {4,6,8,-5}
D) {7,8,2,-5}
Answers
Answer:
C
Step-by-step explanation:
The range of a function is all of the y values of every point. In this case, that is 4, 6, 8, -5 (C). Hope that helps!
Answer:
The answer is C
Step-by-step explanation: 4 and 6 are the medium numbers. -5 and 8 and the lowest and highest nuumbers.
what is (4 to the square root of 81)5?
Answers
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
what is the equation of the line?
Answers
Answer:
y=a
Step-by-step explanation:
Which goes with which
Answers
Please help ASAP! Will give BRAINLIEST! Please read the question THEN answer correctly! No guessing.
Answers
Please help asap! Will give brainliest! Please read the question then answer correctly! No guessing.
Answers
Answer:
A. x - 4
D. x + 8
Step-by-step explanation:
To find the two binomial that are factors of the trinomial, you split the middle term into two:
[tex]x^2[/tex] + 4x - 32
[tex]x^2[/tex] - 4x + 8x - 32
Group:
([tex]x^2[/tex] - 4x) (8x - 32)
Take out GCF (Greatest Common Factor):
x(x - 4) 8(x - 4)
(x + 8) (x - 4)
If h = 85 cm and 1 = 36 cm, what is the length of g?
A. 77 cm
B.
92 cm
C
49 cm
D
75 cm
Answers
Answer:A
Step-by-step explanation:
h=85 f=36
Since it is a right angled triangle we can apply Pythagoras principle to get g
g=√(h^2 - f^2)
g=√(85^2 - 36^2)
g=√(85x85 - 36x36)
g=√(7225 - 1296)
g=√(5929)
g=77
Solve: 3(x - 6) = -12
Answers
Answer:
x=2
Step-by-step explanation:
3*2=6
6-6=0
-12
Prob-4 Pressurized air are being used in a manufacturing company in its daily operation. There are three compressors in service; two-screw type compressors, (S1 ,S2) and one-reciprocal type compressor,(R). Each compressor, at any given time, is either off (0), or on (1) . Assume that event A is denoted to reciprocal compressor (R) that is always off . Event B is denoted that at least one of the screw type of compressor is always on. Assume that all outcomes in event B are equally likely. If P(A∩B)=45% and P(A∪B)=93%. Compute the probability that all compressors are off
Answers
Answer:
The probability that all compressors are off = P(A ∩ B') = 0.18
Step-by-step explanation:
Event A is denoted to reciprocal compressor (R) that is always off.
Event B is denoted that at least one of the screw type of compressor is always on.
P(A) = Probability that the reciprocal compressor is off.
P(A') = Probability that the reciprocal compressor is on.
P(B) = Probability that at least one of the screw type of compressor is on.
P(B') = Probability that at least one of the screw type of compressor is off.
P(A ∩ B) = 45% = 0.45
P(A ∪ B) = 93% = 0.93
P(U) = P(A ∪ B) + P(A' ∩ B')
1 = 0.93 + P(A' ∩ B')
P(A' ∩ B') = 1 - 0.93 = 0.07
The probability that all compressors are off is given as P(A ∩ B')
P(A) = P(A n B') + P(A n B)
P(B) = P(A n B) + P(A' n B)
The question asks us to assume that all outcomes in event B are equally likely.
The possible outcomes in event B include
- The two compressors are on
- First compressor is on, second compressor is off
- Second compressor is on, first compressor is off
- both compressors are off
Since all the outcomes are equally likely, the probability that at least one of the two compressors is on = (3/4) = 0.75 = P(B)
P(B) = P(A n B) + P(A' n B)
0.75 = 0.45 + P(A' n B)
P(A' n B) = 0.75 - 0.45 = 0.30
P(A ∪ B) = P(A ∩ B') + P(A' ∩ B) + P(A ∩ B)
0.93 = P(A ∩ B') + 0.30 + 0.45
P(A ∩ B') = 0.93 - 0.30 - 0.45 = 0.18
Hope this Helps!!!
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
Answers
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
Complete A and B for 5-8 points.
Answers
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
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.
Answers
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
GIVING BRANLIEST Which prism has a greater surface area?
2 prisms. A rectangular prism has a length of 12 inches, height of 8 inches, and width of 6 inches. A triangular prism has a rectangular base with a length of 6 inches and height of 12 inches. 2 rectangular sides are 12 inches by 10 inches. The triangular sides have a base of 6 inches an height of 8 inches.
The rectangular prism has a greater surface area by 72 square inches.
The rectangular prism has a greater surface area by 88 square inches.
The triangular prism has a greater surface area by 72 square inches.
The triangular prism has a greater surface area by 88 square inches.
Answers
Answer:
Rectangular prism
Step-by-step explanation:
Write the expanded form of h(3k-12.4)
Answers
Answer:3hk - 12.4h
Step-by-step explanation:
h(3k-12.4)
h x 3k - h x 12.4
3hk - 12.4h
8 x
105 is how many times as great as 8 x 10-l?
10 4
10 6
10 -4
10 -6
Answers
Answer:
10 6
................
Find the area of the shaded region and choose the appropriate result?
Answers
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!
Solve for a given 2e^a =4b
Answers
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)
Which expression is equivalent to (1/16)^-4?
Answers
Answer:
Answer: Option B. 16^4 is the correct answer.
Step-by-step explanation:
Answer:
Step-by-step explanation:
b
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
Answers
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!
A circle with circumference 8 has an arc with a 288 central angle what is the length of the arc
Answers
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
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
Answers
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
day 2- $1.00
day 3- $2.00
this means every day the amount each student is given doubles from the day before.
day 4- $4.00
day 5- $8.00
day 6- $16.00
day 7- $32.00
day 8- $64.00
day 9- $128.00
so on the 9th day the students would earn $128.00
day 9- $128.00
The value of a car with an initial purchase price of $18,250 depreciates by
11% per year.
Answers
Step-by-step explanation:
This problem on depreciation of price.
Given data
initial price = $18,250
rate of depreciation = 11%
to solve for the new price we must find 11 percent of the initial price (depreciated value) and subtract from the initial price, we have
depreciation=
[tex]\frac{11}{100} *18250\\0.11*18250= 2007.5[/tex]
Hence the depreciation= $2007.50
the new amount is [tex]= initial amount - depreciation[/tex]
[tex]=18250-2007.50\\= 16242.50[/tex]
the new amount is $16242.50
Collete mapped her vegetable garden on the graph below. Each unit represents 1 foot.
Collete plants an 8-foot row of lettuce in the garden. Which points could tell where the row of
lettuce starts and ends?
(-4,-1) and (-4,7)
| (-1, –4) a (
74)
(-1,-6) and (8,-6)
(-6, -1) and (-6,8)
Answers
Answer:
(-4,-1) and (-4,7)Step-by-step explanation:
If Collete planted a row of lettuce, that means their coordinates must have the same vertical coordinate, or the same horizontal coordinate. Another important characteristic is that between those points, there must have 8 units of separation, because it's an 8-foot row.
Only the first choice offers these characteristic to properly represent the row of plants with 8 feet distance between the first and the last plant.
Therefore, the answer is (-4,-1) and (-4,7)
Answer:
(-4, -1) and (-4, 7)
Step-by-step explanation:
I did the quiz
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.
Answers
Answer:
(6,4)
Step-by-step explanation:
I just did quick math in my head.
