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creativ13 [48]
3 years ago
12

Two distinct solid fuel propellants, type A and type B, are being considered for a space program activity. Burning rates of the

propellant are crucial. Random samples of 12 specimens of propellant A are taken with sample means of 84 cm/sec with a standard deviation of 4. And, random samples of 18 specimens of propellant B are taken with sample means of 77 cm/sec with a standard deviation of 6. Find a 99% confidence interval for the difference between the average burning rates for the two propellants. Assume the populations to be approximately normally distributed with equal variances.
Mathematics
1 answer:
Finger [1]3 years ago
6 0

Answer:

C.I. =  (2.297, 11.703)

Step-by-step explanation:

The t-statistic for difference of mean is given by,

t=\frac{\bar{x_{1}}-\bar{x_{2}}}{\sqrt{\frac{s_{1}^{2}}{n_{1}}+\frac{s_{2}^{2}}{n_{2}}}}

Here, \bar{x_{1}} = 84

\bar{x_{2}} = 7

s₁ = 4

n₁ = 12

s₂ = 6

n₂ = 18

Substituting all value in formula,

We get, t = -3.541 at 28 degree of freedom.

Using this formula, we get, t = 1.5342

Therefore, based on the data provided, the 99% confidence interval for the difference between the population means \bar{x_{1}}-\bar{x_{2}} is: 2.297 < \bar{x_{1}}-\bar{x_{2}} < 11.703

which indicates that we are 99% confident that the true difference between population means is contained by the interval (2.297, 11.703)

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Natasha_Volkova [10]

Answer:

y < -3x + 2

Step-by-step explanation:

The shading is below the line meaning the inequality is less than. Moreover, the line is dashed meaning there is no 'equal to'.

Therefore, the inequality is y < -3x + 2.

5 0
2 years ago
Mr. Martin is giving a math test next period. The test, which is worth 100 points, has 29 problems. Each problem is
umka2103 [35]

Answer:

the answer is A. x + y = 29, 5x + 2y = 100

Step-by-step explanation:

just finished the question

6 0
2 years ago
PLEASE HELP WILL MARK BRAINLIEST
mote1985 [20]

Answer:

Step-by-step explanation:

11.81 times 11.81= 139.4761in

6 0
3 years ago
7- a. What is the radius of the circle with center (3,10) that passes through (12,12)?
loris [4]

Answer: a. Radius of circle = \sqrt{85}

b. The equation of this circle : (x-3)^2+(y-10)^2=85

Step-by-step explanation:

Given : Center of the circle = (3,10)

Circle is passing through (12,12).

a. To find the radius we apply distance formula (∵ Radius is the distance from center to any point ion the circle.)

Radius of circle = \sqrt{(12-3)^2+(12-10)^2}

Radius of circle = \sqrt{(9)^2+(2)^2}=\sqrt{81+4}=\sqrt{85}

i.e. Radius of circle = \sqrt{85}

b. Equation of a circle = (x-h)^2+(y-k)^2=r^2 , where (h,k)=Center and r=radius of the circle.

Put the values of (h,k)= (3,10) and r= \sqrt{85} , we get

(x-3)^2+(y-10)^2=(\sqrt{85})^2

(x-3)^2+(y-10)^2=85

∴  The equation of this circle :(x-3)^2+(y-10)^2=85

6 0
3 years ago
Can you solve this? I need help. I don't understand.
ZanzabumX [31]

Answer:

2 sqrt(5) OR 4.5

Step-by-step explanation:

You have to know Pythagorean theorem to solve this question.

a^2 + b^2 = c^2

To use this theorem you have to have a right triangle. There are two right triangles in your image. The lower (larger) one has two sides labeled, so you can use Pythagorean thm to find the third side. There's a short cut, bc some right triangles have easy-to-memorize lengths of the sides. 3-4-5 is one of these number sets. A multiple of this is 6-8-10. We could've solved:

b^2 + 8^2 = 10^2

But it would've come out the same. The unlabeled side is 6.

We can use the 6 and the 4 on the smaller right triangle and use the Pythagorean thm again to solve for x.

4^2 + x^2 = 6^2

16 + x^2 = 36 subtract 16 from both sides.

x^2 = 20

Take the square root of both sides.

sqrt (x^2) = sqrt 20

x = 2 sqrt(5) which is approximately 4.472.

2 sqrt(5) is an exact answer if that is what they are asking for. 4.472 is an approximation to the nearest thousandth. It would be 4.47 to the nearest hundredth or 4.5 to the nearest tenth.

8 0
2 years ago
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