The article "A Shovel with a perforated blade reduces energy expenditure required for digging wet clay" (Human Factors, 2010:492-502) reported on an experiment in which each of 13 workers was provided with both a conventional shovel and a shovel whose blade was perforated with small holes. The authors of the cited article provided the following data on stable energy expenditure (measured in kilocalories per kg of subject per pounds of clay):
1 2 3 4 5 6 7 8 9 10 11 12 13 Worker Conventional 0.0011 0.0014 0.0018 0.0022 0.001 0.0016 0.0028 0.002 0.0015 0.0023 0.0017 0.002 0.0014 Perforated 0.0011 0.001 0.0019 0.0013 0.0011 0.0017 0.0024 0.002 0.0013 0.0017 0.002 0.0013 0.0013 Carry out a test of hypotheses at significance level 0.05 to see whether the true average energy expenditure using the conventional shovel exceeds that using the perforated shovel. (hint: this is a paired-design!). Make sure to calculate a p-value!

Answer:

The z score when x =72 is:

[tex] z = \frac{72-58}{11}= 1.273[/tex]

The mean is 58

This z-score tells you that x= 72 is 1.273 standard deviations to the right of the mearn.

Step-by-step explanation:

Assuming the following info for the question: Suppose John's words per minute on a typing test are normally distributed. Let X -the number of words per minute on a typing test. Then X N(58, 11) If necessary, round to three decimal places.

Provide your answer below rds per minute in a typing test on Sunday. The z score when x =72 is

For this case we know that the variable of interest is modelled with the normal distribution:

[tex]X \sim N (\mu= 58, \sigma=11)[/tex]

And the z score is given by:

[tex] z = \frac{X -\mu}{\sigma}[/tex]

And replacing we got:

[tex] z = \frac{72-58}{11}= 1.273[/tex]

The mean is 58

This z-score tells you that x= 72 is 1.273 standard deviations to the right of the mearn.

Answer:

The correct answer would be F. 7.8

Step-by-step explanation:

the line is more or less a reflection of segment ON

so they are more or less the same.

I hope this helped you!

Answer:

3

I used to be an olimpic runner and I ran the 400 all the time and I did cross country

Answer:

Looks like it's none.

Step-by-step explanation:

[tex]\frac{1}{7}*\frac{1}{8}=\frac{1}{56}[/tex]

Answer:

Step-by-step explanation:B and D I belive.

Answer:

[tex]5(3x-2y-2)[/tex] i think. i am sorry if i am wrong

Step-by-step explanation:

Answer:

24 beads

Step-by-step explanation:

beads in 4 sheet=32

beads in 1 sheet=32/4=8

beads in 3 sheet=8*3=24

Answer:

Assuming that you can make the same number of beads with 1 sheet of paper, Tameka can make 24 beads with 3 sheets of paper.

Answer:

61%

Step-by-step explanation:

16/26 x 100 = 61.538461

You have to round it up if the question tells you to round it up.

hope it helps! :)

Answer:

62%

Step-by-step explanation:

42 x 62% = 26.04

I am sorry if you get this wrong. I really hope this helps.

Answer:

[tex]20.25 \: m^2[/tex]

Step-by-step explanation:

Use the formula for the area of a square.

[tex]A=s^2[/tex]

Where [tex]s=4.5[/tex]

[tex]s^2\\(4.5)^2\\20.25[/tex]

The area of the square is 20.25 square meters as per the concept of the square.

To find the area of a square, we need to square the length of one of its sides. In this case, the side length is given as 4 1/2 meters.

First, we need to convert the mixed number 4 1/2 into an improper fraction. We can rewrite it as 9/2.

Next, we square the side length:

[tex]\frac{9}{2}^2 = \frac{81}{4}[/tex].

To simplify the fraction, we can divide the numerator by the denominator:

81 ÷ 4 = 20 remainders 1.

Therefore, the area of the square is 20 1/4 square meters.

However, we can simplify the mixed number further. Since 4 can be divided by 4 and 1 can be divided by 4, we have:

20 1/4

= 20 + 1/4

= 20 + 1/4

= 20 + 0.25

= 20.25.

Therefore, the area of the square is 20.25 square meters.

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Answer:

[tex]\$0.26[/tex] has to be paid more if the coupon is applied first

Step-by-step explanation:

Given: A grocery store has a discount of 13% off hand soap. At the same time the hand soap manufacturer has a coupon for $2.00 off.

To find: how much more would be paid if the coupon is applied first

Solution:

Let $ x denotes cost of hand soap

Case 1:

If the discount is given first,

cost of hand soap = [tex]x-\frac{13}{100} x=\$ \frac{87}{100}x[/tex]

If the coupon for $2.00 off is applied,

Final cost of the hand soap = [tex]\$\,(\frac{87}{100}x-2)[/tex]

Case 2:

If the coupon for $2.00 off is applied first,

cost of hand soap = [tex]\$(x-2)[/tex]

If the discount is given then,

final cost of the hand soap = [tex](x-2)-\frac{13}{100}(x-2)=\frac{87}{100}(x-2)[/tex] = [tex]\frac{87}{100}x-\frac{87}{50}[/tex]

Here,

[tex]\frac{87}{100}x-\frac{87}{50}-\frac{87}{100}x+2=\frac{13}{50}=\$0.26[/tex]

So, [tex]\$0.26[/tex] has to be paid more if the coupon is applied first.

Answer:

$0.26

Step-by-step explanation: I took the test

Answer:

  tan(x) = -1/6

Step-by-step explanation:

We can use the relation between tan and sec:

  [tex]\displaystyle\tan{x}=\pm\sqrt{\sec^2{x}-1}\\\\\tan{x}=-\sqrt{\left(\dfrac{\sqrt{37}}{6}\right)^2-1}\quad\text{negative because sine is negative}\\\\=-\sqrt{\dfrac{37-36}{36}}=\boxed{-\dfrac{1}{6}}[/tex]

The tangent of x is -1/6.

Answer:

y = x + 5

Step-by-step explanation:

Perpendicular slope is opposite inverse so the perpendicular slope to -1x would be 1x

Then find b in y=mx+b

Plug in all the number

y=-9

x=-4

m=1

So, -4=1(-9)+b

1×-9=-9

+9 to both sides

5=b

Therefore,

y=x+5

Answer:

4.8

Step-by-step explanation:

simple interest=Principal ×time×rate ÷100

=24×4×5÷100

=4.8

Answer: idk

Step-by-step explanation:

idk

Answer:

x = 27

Step-by-step explanation:

x/9 = 3

Multiply each side by 9

x/9 * 9 = 3*9

x = 27

Answer:

27

Step-by-step explanation:

x/9= 3

Carry over the 9 and make x the subject.

x= 3*9

x= 27

Therefore x is 27.

To check if the answer is correct, replace the x with the value of what it is in brackets. The value of x is 27.

(27)/9= 3

= 27/9

= 3

We got back the 3 so that means the answer is correct

Answer:

A=12 feet²

Step-by-step explanation:

1/2*base*height=area

(1/2)*4*6=12

Answer:

508

Step-by-step explanation:

use l x w

40x7

10x18

8x6

508

Answer:

Graph 2

Step-by-step explanation:

You can see that all the shaded numbers are above negative 25 in that graph. Hope this helped!

Answer:=

1 7/18

Step-by-step explanation:

Turn the improper fraction into a mixed fraction.

The question is incomplete. Here is the complete qeustion.

In a sample of seven cars, each car was tested for nitrogen-oxide emissions (in grams per mile) and the following results were obtained: 0.10 0.13 0.16 0.15 0.14 0.008 0.15

(a) Construct a 99% confidence interval for the mean nitrogen-oxide emissions of all cars.

(b) If the EPA requires that nitrogen-oxide emissions be less than 0.165 g/mi, based on the 99% confidence interval in (a), can we safely conclude that this requirement is being met?

Answer: (a) 0.089 ≤ μ ≤ 0.171

(b) No

Step-by-step explanation:

(a) To determine the confidence interval, first calculate the mean (X) and standard deviation (s) of the sample

X = [tex]\frac{0.1+0.13+0.16+0.15+0.14+0.08+0.15}{7}[/tex]

X = 0.13

s = [tex]\sqrt{\frac{(0.1-0.13)^{2} + (0.13 - 0.13)^{2} + ... + (0.15 - 0.13)^{2}}{7-1} }[/tex]

s = 0.029

The degrees of freedom is

N - 1 = 7 - 1 = 6

And since the confidence is of 99%:

α = 1 - 0.99 = 0.01

α/2 = 0.01/2 = 0.005

The t-test statistics for [tex]t_{6,0.005}[/tex] is 3.707

(Value found in the t-distribution table)

Now, calculate Error:

E = [tex]t_{6,0.005}[/tex] . [tex]\frac{s}{\sqrt{N} }[/tex]

E = 3.707. [tex]\frac{0.029}{\sqrt{7} }[/tex]

E = 0.041

The interval will be:  

0.13 - 0.041 ≤ μ ≤ 0.13+0.041

0.089 ≤ μ ≤ 0.171

(b) No, because according to the interval, the nitrode-oxide emissions range from 0.089 to 0.171, which is greater than required by EPA.

Answer:

$4,000,000

Step-by-step explanation:

20,000*200=4,000,000

Answer:

-3 ( x+2i) (x-2i)

Step-by-step explanation:

-3x^2-12

Factor out a -3

-3(x^2 +4)

Rewrite

-3 ( x^2 - -4)

-3 ( x^2 - (-2i)^2)  This is the difference of squares ( a^2 -b^2 ) = (a-b)(a+b)

-3 ( x- -2i) (x+2i)

-3( x+2i) (x-2i)

Answer: Option A.

Step-by-step explanation:

Here we have two equations for the circumference, one for each circle:

C = 2*pi*r

C' = 2*pi*r'

now, if we take the quotient of those two equations, the left side must still be equal to the left side, this means that:

C/C' = 2*pi*r/(2*pi*r') = r/r'

So we have the relation:

C/C' = r/r'

And this is obtained for the division property of equality.

IF A = B, then as both numbers are equal, if we divide both sides by the same thing, then the equality must remain true.

Then the correct option is A.

Answer:

Option (A).

Step-by-step explanation:

We choose a point from table of f(x), that is (-2, -31)

1). If this point is reflected across x-axis, rule to be followed,

(x, y) → (x, -y)

That means y coordinate of the point gets changed with opposite notation.

If (-2, -31) is reflected over the x-axis,

(-2, -31) → (-2, 31) ----------(1)

2). When a point is reflected over the y-axis,

Rule to be followed,

(x, y) → (-x, y)

(-2, -31) → (2, -31) ----------(2)

3). When a point is reflected over the line y = x

Rule to be followed,

(x, y) → (y, x)

(-2, -31) → (-31, -2) -----------(3)

By comparing f(x) and g(x) we find the relation between the functions as,

f(-2, -31) → g(2, -31)

Rule between the functions f and g matches with the rule number (2).

Therefore, function 'f' has been reflected across y axis to get the function 'g'.

Option (A) will be the answer.

Answer:

The group that has greater value of relative dispersion is the smokers group, as the coefficient of variationof their data is bigger than the coefficient of variation of the non-smokers group data.

CV smokers: 0.387

CV non-smokers: 0.234

Step-by-step explanation:

We will calculate the relative dispersion of each data set with its coefficient of variation (ratio of the standard deviation to the arithmetic mean).

Then, first we calculate the mean and standard deviation for the smokers data:

Mean: 43.7

Standard deviation: 286.5

[tex]M_s=\dfrac{1}{n}\sum_{i=1}^n\,x_i\\\\\\M_s=\dfrac{1}{12}(69.3+56+22.1+47.6+53.2+. . .+13.8)\\\\\\M_s=\dfrac{524.4}{12}\\\\\\M_s=43.7\\\\\\s_s=\dfrac{1}{n-1}\sum_{i=1}^n\,(x_i-M_s)^2\\\\\\s_s=\dfrac{1}{11}((69.3-43.7)^2+. . . +(13.8-43.7)^2)\\\\\\s_s=\dfrac{3152}{11}\\\\\\s_s=286.5\\\\\\[/tex]

The mean and standard deviation for the non-smokers is:

Mean: 30.3

Standard deviation: 50.9

[tex]M_n=\dfrac{1}{n}\sum_{i=1}^n\,x_i\\\\\\M_n=\dfrac{1}{15}(28.6+25.1+26.4+34.9+28.8+. . .+13.9)\\\\\\M_n=\dfrac{453.8}{15}\\\\\\M_n=30.3\\\\\\s_n=\dfrac{1}{n-1}\sum_{i=1}^n\,(x_i-M_n)^2\\\\\\s_n=\dfrac{1}{14}((28.6-30.3)^2+. . . +(13.9-30.3)^2)\\\\\\s_n=\dfrac{713.3}{14}\\\\\\s_n=50.9\\\\\\[/tex]

Now, we can calculate the coefficient of variation:

CV smokers:

[tex]CV_s=\dfrac{s_s}{M_s}=\dfrac{16.9}{43.7}=0.387[/tex]

CV non-smokers:

[tex]CV_n=\dfrac{s_n}{M_n}=\dfrac{7.1}{30.3}=0.234[/tex]

Answer:

Can you give the question. Can you post the picture. I can help solve. I will edit this answer once you have given the question/picture.

Answer:

x =30.4 seconds

Step-by-step explanation:

We can use ratios to solve

20 drops           8 drops

---------------  = ----------------

76 seconds      x seconds

Using cross products

20x = 8*76

20x =608

Divide each side by 20

20x/20 = 608/20

x =30.4 seconds

Answer:

30.4 secs = 30secs

Step-by-step explanation:

20 drops fall in 76s

Hence 1 drop is 76/20

Therefore 8 drops would be ;

76/20 × 8 = 30.4 secs

Answer:

160 yards

Step-by-step explanation:

P=2l+2w

P=2(3w-8)+2(w)

432=2(3w-8)+2(w)

432=6w-16+2w

432=8w-16

432+16=8w

448=8w

w=448/8

w=56yards

l=3(56)-8

l=168-8=160yards

Answer:

26.68% probability that exactly three will end up being replaced under warranty

Step-by-step explanation:

For each telephone under warranty, there are only two possible outcomes. Either they need to be replaced, or they do not need to be replaced. Each telephone is independent of other telephones. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

30% must be replaced with new units

This means that [tex]p = 0.3[/tex]

If a company purchases ten of these telephones, what is the probability that exactly three will end up being replaced under warranty

This is [tex]P(X = 3)[/tex] when [tex]n = 10[/tex]. So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 3) = C_{10,3}.(0.3)^{3}.(0.7)^{7} = 0.2668[/tex]

26.68% probability that exactly three will end up being replaced under warranty

Answer:

1/4845

Step-by-step explanation:

The probability of selecting a defective cog first is

1/5

The second cog is

3/19

The third cog is

1/9

And the fourth cog is

1/17

Multiplying these together we get

1/5 * 3/19* 1/9 * 1/17  = 1/4845

The probability of selecting 4 cogs from the 20 produced where all are defective is approximately 0.000206.

Probability is a measure of how likely an event is to occur. Many events are impossible to predict with absolute certainty.

The probability of selecting 4 defective cogs from the 20 produced can be calculated as follows:

P(4 defective cogs) = (Number of ways to select 4 defective cogs) / (Total number of ways to select 4 cogs from 20)

The number of ways to select 4 defective cogs can be found by selecting 4 defective cogs out of the 4 defective cogs produced, and 0 non-defective cogs out of the remaining 20-4=16 non-defective cogs. This can be expressed mathematically as:

Number of ways to select 4 defective cogs = (4 choose 4) * (16 choose 0) = 1

The total number of ways to select 4 cogs from 20 can be found by selecting 4 cogs out of the 20 produced. This can be expressed mathematically as:

Total number of ways to select 4 cogs from 20 = (20 choose 4) = 4845

Therefore, the probability of selecting 4 defective cogs from the 20 produced is:

P(4 defective cogs) = (Number of ways to select 4 defective cogs) / (Total number of ways to select 4 cogs from 20) = 1/4845

Thus, the probability of selecting defective cogs is approximately 0.000206.

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