Two random samples of 30 individuals were selected. One sample participated in an activity which simulates hard work. The average breath rate of these individuals was 17 breaths per minute. The other sample did some normal walking. The mean breath rate of these individuals was 14. Find the 90% confidence interval of the difference in the breath rates if the population standard deviation was 4.2 for breath rate per minute.

Answers

Answer 1

Answer:

[tex] (17-14) -1.64 \sqrt{\frac{4.2^2}{30} +\frac{4.2^2}{30}}=1.222[/tex]

[tex] (17-14) +1.64 \sqrt{\frac{4.2^2}{30} +\frac{4.2^2}{30}}=4.778[/tex]

So then we can conclude at 90% of confidence that the difference in the two means is between 1.222 and 4.778 beats per minute

Step-by-step explanation:

For this case we have the following info given:

[tex] \bar X_1 = 17[/tex] sample mean for the first sample

[tex] \bar X_2 = 14[/tex] sample mean for the second sample

[tex]\sigma =4.2[/tex] represent the population deviation

[tex] n_1= n_2 =30[/tex] represent the sample size ofr each case

We can construct the confidence interval for the difference of means with the following formula:

[tex] (\bar X_1 -\bar X_2) \pm z_{\alpha/2} \sqrt{\frac{\sigma^2_1}{n_1} +\frac{\sigma^2_2}{n_2}}[/tex]

And the confidence for this case is 90% or 0.9 so then the significance level is [tex]\alpha=1-0.9=0.1[/tex] and [tex]\alpha/2 =0.05[/tex] the critical value for this case is:

[tex] z_{\alpha/2}=1.64[/tex]

And replacing we got:

[tex] (17-14) -1.64 \sqrt{\frac{4.2^2}{30} +\frac{4.2^2}{30}}=1.222[/tex]

[tex] (17-14) +1.64 \sqrt{\frac{4.2^2}{30} +\frac{4.2^2}{30}}=4.778[/tex]

So then we can conclude at 90% of confidence that the difference in the two means is between 1.222 and 4.778 beats per minute


Related Questions

2 people can paint a fence in one hour, how long would it take 10 people, give your answer in minutes

Answers

Answer:

5 hours=300minutes

Step-by-step explanation:

10/2=5 hours

To find the answer in minutes do

50*60 becuase there are 60 minutes in 1 hour.

5*60=300min

Answer:

12 minutes

Step-by-step explanation:

2 people=60 minutes

÷2             ×2

1 people=120 minutes

×10           ÷10

10 people=12 minutes

SOMEONE PLEASE HELP ???

Which of the following proportionality statements is correct ?

Answers

Answer:

The third one is correct

Step-by-step explanation:

In ΔHIJ, the measure of ∠J=90°, HI = 6.6 feet, and IJ = 2.9 feet. Find the measure of ∠H to the nearest degree.

Answers

Answer:

26

Step-by-step explanation:

Answer:

26

Step-by-step explanation:

sinH= hypotenuse/opposite = (2.9/6.6)

H = sin^-1 ( 2.9/6.6)

​H=26.065≈26

Find the surface area of the triangular prism shown below. 5x6x7

Answers

Answer:

5 times 6 is 30 and 30 times 7 is 210

so 210 is your anser hop that helps

Answer:

210

Step-by-step explanation: First way: 5x6=30x7=210

2nd way/distributive property: 5(6x7) 5(6=30x7=210.

Check all of the expressions that are equal to the one below.

(8 + 7). 11

A. 11. (8 + 7)

B. 8•(11)-7•(11)

C. 11•(7) + 11 (8)

D. 8+ (711)

Answers

Answer:

  A. 11•(8 + 7)

  B. 8•(11)-7•(11)

  C. 11•(7) + 11•(8)

Step-by-step explanation:

The commutative property of multiplication lets you swap the order of the factors in the product:

  (8 +7)•11 = 11•(8 +7)

The distributive property lets you eliminate parentheses:

  (8 +7)•11 = 8•11 +7•11

And the commutative properties of addition and multiplication let you rearrange this sum of products to ...

  (8 +7)•11 = 11•7 +11•8

In ΔQRS, q = 1.3 inches, r = 1.6 inches and ∠S=157°. Find the length of s, to the nearest 10th of an inch.

Answers

Answer:

2.8

Step-by-step explanation:

using cosine rule

[tex]s^{2}[/tex] = [tex]1.3^{2} + 1.6^{2} - 2(1.3)(1.6)cos 157[/tex]

s = [tex]\sqrt{8.0793}[/tex] = 2.842 = 2.8


Find number x, if when you add 7 to it and double the result you get 19 more than x.
NEED HELP ASAP

Answers

Answer:

x = 5.

Step-by-step explanation:

We can set up equivalent equations like this to solve:

2(x + 7) = x + 19

Distribute the 2, giving us:

2x + 14 = x+ 19

Move the variables to one side, and the numbers to the other, giving us:

x = 5

Select the correct answer.

Consider the given solids with the dimensions shown. Which solids are similar?

three triangular prisms. Figure 1 has a right triangle base that is 9 meters by 12 meters and a height of 16 meters, figure 2 has a right triangle base that is 12 meters by 16 meters and a height of 18 meters, and figure 3 has a right triangle base that is 36 meters by 48 meters and a height of 64 meters.
Figures not drawn to scale

A.
only figure 1 and figure 2
B.
only figure 2 and figure 3
C.
only figure 1 and figure 3
D.
all three figures
E.
none of the figures

Answers

Answer:

Only Figure 1 and Figure 3 Are Similar.

Step-by-step explanation:

Figure 1 and Figure 3 are proportional by 1:4 while the Figure 2 is not proportional to any of them.

There is a bag filled with 3 blue, 4 red and 5 green marbles.
A marble is taken at random from the bag, the colour is noted and then it is replaced.
Another marble is taken at random.
What is the probability of exactly 1 red?

Answers

Answer:

22.22%

Step-by-step explanation:

If it is exactly a red, it means that it is removed on the first or second attempt, but only once, in this case it does not matter if it is on the first or second attempt because the marble is returned to the bag.

So suppose that on the first attempt red is drawn, the probability would be:

4 / (3 + 4 + 5) = 4/12 = 1/3

Now, on the second attempt, it is not to draw a red, it must be green or blue, so it would be:

(5 + 3) / (3 + 4 + 5) = 8/12 = 2/3

The final probability then is:

1/3 * 2/3 = 0.2222

that is, the probability is 22.22%

Write the contrapositive of the conditional statement. Determine whether the contrapositive is true or false. If it is false, find a counterexample.


Two angles measuring 180 are supplementary.

Answers

Answer: A converse statement is formed by exchanging the hypothesis and conclusion of the conditional.

Step-by-step explanation:

Joel had 4 liters of water. He drank 2.7 liters of water while he was hiking. How many liters does Joel have left?

Answers

Answer:

1.3 liters are left

Step-by-step explanation:

Take the amount of water he had and subtract the amount of water he drank

4.0

-2.7

-----------

Borrow

3.10

-2.7

-----------

1.3 liters are left

Answer:

1.3 liters

Step-by-step explanation:

In the given question: "Joel had 4 liters of water, and drank 2.7 liters of water while he was hiking. "

Subtract the total before the hike by the amount he drank during the hike.

[tex]4-2.7=1.3[/tex]

Joel should have 1.3 liters left.

ASAP! GIVING BRAINLIEST! Please read the question THEN answer correctly! No guessing. Show your work or give an explaination.

Answers

Answer:

B. [tex]f(x)=-(x-4)^{2} -3[/tex]

Step-by-step explanation:

[tex]f(x)=x^{2}[/tex]

The transformations are:

Reflected upon the x axis (x is now negative):

[tex]f(x)=-x^{2}[/tex]

Moved 4 units to the right (instead of just the variable x, you have (x-4)):

[tex]f(x)=-(x-4)^{2}[/tex]

And finally moved 3 units down (so now it's minus 3):

[tex]f(x)=-(x-4)^{2} -3[/tex]

Hope this helps! :]


a =4
5

b =3
2
Work out a - 2b as a column vector.

Answers

Answer:

[-2; 1 ] is the new column vector

Step-by-step explanation:

See explanation in the attachment.

The value of a-2b as a column vector is [tex]\left[\begin{array}{c}-2&1\end{array}\right][/tex] .

What is a matrix?

A matrix is an arrangement of numbers, expressions or symbols arranged in rows and columns as a rectangular array. These rows and columns define the size or dimension of a matrix.

For the given situation,

The matrix is

[tex]a=\left[\begin{array}{c}4&5\end{array}\right][/tex] , [tex]b=\left[\begin{array}{c}3&2\end{array}\right][/tex]

The operation is a - 2b. The matrix becomes

⇒ [tex]a-2b=\left[\begin{array}{c}4&5\end{array}\right] -2\left[\begin{array}{c}3&2\end{array}\right][/tex]

⇒ [tex]a-2b=\left[\begin{array}{c}4&5\end{array}\right] -\left[\begin{array}{c}6&4\end{array}\right][/tex]

⇒ [tex]a-2b=\left[\begin{array}{c}-2&1\end{array}\right][/tex]

Hence we can conclude that the value of a-2b as a column vector is [tex]\left[\begin{array}{c}-2&1\end{array}\right][/tex] .

Learn more about matrices here

https://brainly.com/question/18291235

#SPJ3

1f 3/4 gallon of paint can cover 1/8 of the fence how many gallons will he need to paint the whole fence

Answers

Answer:

He will need 6 gallons of painting to paint the whole fence.

Step-by-step explanation:

Since 3/4 gallon of paint covered 1/8 of the fence, we have to multiply 3/4 by 8 in order to find the number of gallons that will paint the whole fence (because 8 x 1/8 = 1)

[tex]\frac{3}{4}[/tex] x [tex]\frac{8}{1}[/tex] = [tex]\frac{24}{4}[/tex] = 6

Hope this helps!

The mean SAT score in mathematics, M, is 600. The standard deviation of these scores is 48. A special preparation course claims that its graduates will score higher, on average, than the mean score 600. A random sample of 70 students completed the course, and their mean SAT score in mathematics was 613.
a) At the 0.05 level of significance, can we conclude that the preparation course does what it claims? Assume that the standard deviation of the scores of course graduates is also 48.

Answers

Answer:

Step-by-step explanation:

The mean SAT score is [tex]\mu=600[/tex], we are going to call it \mu since it's the "true" mean

The standard deviation (we are going to call it [tex]\sigma[/tex]) is

[tex]\sigma=48[/tex]

Next they draw a random sample of n=70 students, and they got a mean score (denoted by [tex]\bar x[/tex]) of [tex]\bar x=613[/tex]

The test then boils down to the question if the score of 613 obtained by the students in the sample is statistically bigger that the "true" mean of 600.

- So the Null Hypothesis [tex]H_0:\bar x \geq \mu[/tex]

- The alternative would be then the opposite [tex]H_0:\bar x < \mu[/tex]

The test statistic for this type of test takes the form

[tex]t=\frac{| \mu -\bar x |} {\sigma/\sqrt{n}}[/tex]

and this test statistic follows a normal distribution. This last part is quite important because it will tell us where to look for the critical value. The problem ask for a 0.05 significance level. Looking at the normal distribution table, the critical value that leaves .05% in the upper tail is 1.645.

With this we can then replace the values in the test statistic and compare it to the critical value of 1.645.

[tex]t=\frac{| \mu -\bar x |} {\sigma/\sqrt{n}}\\\\= \frac{| 600-613 |}{48/\sqrt(70}}\\\\= \frac{| 13 |}{48/8.367}\\\\= \frac{| 13 |}{5.737}\\\\=2.266\\[/tex]

since 2.266>1.645 we  can reject the null hypothesis.

Answer:

The null hypothesis is that the SAT score is not significantly different for the course graduates.

Alternate hypothesis: there is a significant difference between the SAT score achieved by the course graduates as compared to the non-graduates.

Apply the t-test. The Test Statistic value comes out to be t = 1.738 and the p-value = 0.0844

Since the p-value is larger than 0.05, the evidence is weak and we fail to reject eh null hypothesis.

Hope that answers the question, have a great day!

AB=6CM AC= 12cm
calculate the length of CD

Answers

AB=6cm AC=12cm

AC² = AB + BC²

12² = 6² + CB²

CB² = 12² - 6²

CB² = 144 - 36

CB² = 108

CB = √ 108 cm.

sin 55° = CB / CD

0.81915 = √108 / CD

CD = 10.392 / 0.81915

CD = 12.686 cm

Answer:

Step-by-step explanation:

This was a question on mathswatch, so I’ve done this.

You need to round to 3 significant numbers

AB=6cm AC=12cm

AC² = AB + BC²

12² = 6² + CB²

CB² = 12² - 6²

CB² = 144 - 36

CB² = 108

CB = √ 108 cm.

sin 55° = CB / CD

0.81915 = √108 / CD

CD = 10.392 / 0.81915

CD = 12.686 cm

CD = 12.7 cm

How many pieces of tape 5mm long can be cut from a piece 15cm long ?

Answers

Answer:

A piece of tape: 15cm =150mm

=> The number of tape 5mm that could be cut: N = 150/5 = 30

Hope this helps!

:)

Suppose an airline claims that its flights are consistently on time with an average delay of at most 15 minutes. It claims that the average delay is so consistent that the variance is no more than 150 minutes. Doubting the consistency part of the claim, a disgruntled traveler calculates the delays for his next 25 flights. The average delay for those 25 flights is 22 minutes with a standard deviation of 15 minutes. A chi-square test was performed. Graph the situation. Label and scale the horizontal axis. Mark the mean and test statistic. Shade the p-value.

Answers

Answer:

The p-value will be "0.0549".

Step-by-step explanation:

The given values are:

Time, t = 15 minutes

Df, σ = 25-1 = 24

Now,

⇒  [tex]H_{0}:\sigma^2\leq 150[/tex]

and,

⇒  [tex]H_{1}:\sigma^2>150[/tex]

As we know,

Chi square = [tex]\frac{(n-1)s^2}{(\sigma^2)}[/tex]

On putting the values in the above formula, we get

⇒                = [tex]\frac{24\times 15^2}{150}[/tex]

⇒                = [tex]\frac{24\times 225}{150}[/tex]

⇒                = [tex]36[/tex]

Therefore, p-value = 0.0549

The p-value determined > 0.05, the null hypothesis also isn't dismissed at point 0.05.

Solve the equation and express each solution in a + bi form.
x - 7² – 8=0

Answers

Answer:

x + 57i

Step-by-step explanation:

x - 7² – 8=0

x -49-8

x - 57 = x + 57(-1) ; i = -1( complex number notation)

x + 57i

Two models of the same compound are shown.


In what way is Model A better than Model B?

Model A shows the types of elements in the compound, but Model B does not.

Model A shows the total number of atoms in the molecule, but Model B does not.

Model A shows the three-dimensional shape of the molecule, but Model B does not.

Model A shows the number of atoms of each element in the molecule, but Model B does not.

Answers

Answer:

Step-by-step explanation:

Model B shows how the atoms in the molecule are connected, but Model A does not.

it is C

just did the test

Multiple choices answer and explain the solution?

Answers

Answer:

associative property of multiplication

Step-by-step explanation:

You cant rlly explain, you just have to know your properties

Rewrite in logarithmic form 19^2 = 361

Answers

Answer:

  [tex]\log_{19}{361}=2[/tex]

Step-by-step explanation:

We know that taking logarithms performs the transformation ...

  [tex]b^e=x\\\\e\cdot\log{b}=\log{x}\quad\text{take logs}\\\\e=\dfrac{\log{x}}{\log{b}}\quad\text{divide by $\log{b}$}\\\\\log_b{x}=e\quad\text{use the change of base formula}[/tex]

Then for b=19, e=2, x=361, we have

  [tex]\boxed{\log_{19}{361}=2}[/tex]

5. Which is equivalent to 1/2
? Select all that apply.
A sin 30°
B sin 45°
C cos 45°
D cos 60°
E tan 30°
F tan 45º

Answers

Answer:

A  sin 30°D  cos 60°

Step-by-step explanation:

Attached is a short table of trig function values. There are really only three you need to remember if you keep an image of the sine and cosine graphs in your head (for 0° and 90° values).

  sin(α) = cos(90°-α)

  tan(α) = sin(α)/cos(α)

__

  sin(30°) = cos(60°) = 1/2 . . . . . . . the answer to this question

  sin(45°) = cos(45°) = 1/√2 = (√2)/2

  sin(60°) = cos(30°) = (√3)/2

__

I find it just as easy to remember SOH CAH TOA and the side ratios in isosceles and half-equilateral right triangles: 1:1:√2 and 1:√3:2, respectively.

If you bought a stock last year for a price of $141,and it has risen 1.8% since then,
how much is the stock worth now, to nearest cent?

Answers

Answer:

Current worth of stock is $141.538

Current worth of stock rounded to nearest cent is $142

Step-by-step explanation:

price of stocks= $141

percentage increase in price of stocks = 1.8% of initial price of stock

dollar value increase in price of stocks = 1.8% of initial price of stock

increase in price of stocks = 1.8% of  $141

increase in price of stocks = 1.8/100 * $141 =$ 253.8/100 = $2.538

Current worth of stock = initial price of stock+increase in price of stocks

substituting the value of initial price of stock and increase in price of stocks we have

Current worth of stock =$141 + $2.538 = $141.538

Since we need to find stock worth now, to nearest cent, as after decimal there .5 and any value greater than or equal to .5 is rounded to one then after rounding,  $141.538 becomes  $142

Which expression is equivalent to 3\dfrac78 - 6\dfrac143 8 7 ​ −6 4 1 ​ 3, start fraction, 7, divided by, 8, end fraction, minus, 6, start fraction, 1, divided by, 4, end fraction?

Answers

Answer:

[tex]-2\dfrac{3}{8}[/tex]

Step-by-step explanation:

Given the expression:

[tex]3\dfrac78 - 6\dfrac14[/tex]

We are to simplify and obtain an equivalent expression.

Step 1: Change to Improper Fractions

[tex]3\dfrac78 - 6\dfrac14=\dfrac{31}{8}-\dfrac{25}{4}[/tex]

Step 2: Take the Lowest Common multiple of the denominators

LCM of 8 and 4 is 8.

Therefore:

[tex]\dfrac{31}{8}-\dfrac{25}{4}=\dfrac{31-2(25)}{8}\\\\\dfrac{31-50)}{8}\\\\=-\dfrac{19}{8}\\\\=-2\dfrac{3}{8}[/tex]

Therefore, an equivalent expression to [tex]3\dfrac78 - 6\dfrac14[/tex] is [tex]-2\dfrac{3}{8}[/tex].

Answer

3  7/8+ (-6  1/4)

Step-by-step explanation:

The__ of a circle centered at the origin measures the distance from the origin to any point on the circle.

Answers

Answer:

the radius

Step-by-step explanation:

Answer:

radius

Step-by-step explanation:

a.756
b.936
c.1,008
d.1,080
HELLLPPPPP

Answers

Answer:

936 is the correct option

Step-by-step explanation:

calm down !!!we know that the volume of cuboid is l×b×h=10×(10-2)×9=10×8×9=720now again the volume of cuboid (bottom) is l×b×h=12×9×2=216the total volume is cuboid(up) + cuboid (bottom)=720+216=936 which is b

A video company randomly selected 100 of its subscribers and asked them how many hours of shows they watch per week. Of those surveyed 35 watch more than 10 hours per week. Based on the data, if the company has 3,000 subscribers, how many watch more than 10 hours per week?

Answers

Hello there!

35/100 watch more then 10 hours a week

3000 is 30 times greater than 100 so we can simply multiply 35/100 by 30.

35/100 x 30 = 1050/3000

Therefore, if the company had 3,000 subscribers, 1,050 subscribers would be watching more than 10 hours a week.

what is the equation of a straight line is parallel to y = 4x-1?

Answers

Answer: i dont know

Step-by-step explanation:

t(x) = ax^5 + 2 where is a real number. If the points (-2, 66) and (2, -62) are on the graph of the function classify as one of the following.

0 < a < 1
a < -1
a > 1
0 > a > -1

Answers

Answer:

a < -1

Step-by-step explanation:

Okay, so we are given this equation:

t(x) = ax^5 + 2

Lets plug in -2 as x and see what happens.. t(x) can be 66..

[tex]a * (-2)^{5} + 2[/tex] = 66

-32a + 2 = 66

-32a = 64

a = -2

A is less than -1,

a < -1

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