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stealth61 [152]

3 years ago

11

How to find circumference

1 answer:

Karo-lina-s [1.5K]3 years ago

4 0

To calculate the circumference of a circle, multiply the diameter of the circle with π (pi). The circumference can also be calculated by multiplying 2×radius with pi (π=3.14). c=2πr

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Are 2/3 and 5/6 equivalent ratios. Justify your answer

Natali5045456 [20]

No because u would multiply to get a common denominator and it would be 4/6 5/6

3 0

3 years ago

Read 2 more answers

Cable Strength: A group of engineers developed a new design for a steel cable. They need to estimate the amount of weight the ca

KatRina [158]

Answer:

95% confidence interval for the mean breaking strength of the new steel cable is [763.65 lb , 772.75 lb].

Step-by-step explanation:

We are given that the engineers take a random sample of 45 cables and apply weights to each of them until they break. The mean breaking weight for the 45 cables is 768.2 lb. The standard deviation of the breaking weight for the sample is 15.1 lb.

Since, in the question it is not specified that how much confidence interval has be constructed; so we assume to be constructing of 95% confidence interval.

Firstly, the Pivotal quantity for 95% confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean breaking weight = 768.2 lb

s = sample standard deviation = 15.1 lb

n = sample of cables = 45

$\mu$ = population mean breaking strength

Here for constructing 95% confidence interval we have used One-sample t test statistics as we don't know about population standard deviation.

<u>So, 95% confidence interval for the population mean, </u> $\mu$ <u> is ;</u>

P(-2.02 < $t_4_4$ < 2.02) = 0.95 {As the critical value of t at 44 degree

of freedom are -2.02 & 2.02 with P = 2.5%}

P(-2.02 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 2.02) = 0.95

P( $-2.02 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $2.02 \times {\frac{s}{\sqrt{n} } }$ ) = 0.95

P( $\bar X-2.02 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.02 \times {\frac{s}{\sqrt{n} } }$ ) = 0.95

<u>95% confidence interval for</u> $\mu$ = [ $\bar X-2.02 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+2.02 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $768.2-2.02 \times {\frac{15.1}{\sqrt{45} } }$ , $768.2+2.02 \times {\frac{15.1}{\sqrt{45} } }$ ]

= [763.65 lb , 772.75 lb]

Therefore, 95% confidence interval for the mean breaking strength of the new steel cable is [763.65 lb , 772.75 lb].

3 0

4 years ago

Please answer ASAP! An explanation is a MUST REQUIREMENT in order to receive points and the Brainliest answer. Thank you.

Komok [63]

Hello,

Magnetude is the norm of the vector=V13
Polar angle=arctan(2/3) ==>33.69...°

6 0

3 years ago

What is the measure of this angle?<br> 90 degrees<br> 115 degrees<br> 180 degrees<br> 40 degrees

erma4kov [3.2K]

Answer:

90

Step-by-step explanation:

5 0

4 years ago

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Going against the current, a boat takes 6 hours to make a 120-mile trip. When the boat travels with the current on the return tr

tankabanditka [31]

Answer:

22 miles per hour

Step-by-step explanation:

Against the current, the boat's rate of travel is ...

(120 mi)/(6 h) = 20 mi/h

With the current, the boat's rate of travel is ...

(120 mi)/(5 h) = 24 mi/h

___

The sum of boat speed (b) and current speed (c) is 24 mph. The difference is 20 mph. This lets us write the equations ...

b + c = 24

b - c = 20

Adding these two equations together, we get ...

2b + 0c = 44

b = 22 . . . . . . . . divide by 2

The rate of the boat in still water is 22 miles per hour.

5 0

4 years ago