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3 years ago

Which of the following names a line segment in the drawing?

Mathematics

1 answer:

alekssr [168]3 years ago

6 0

The answer is JN. A way I try to remember a line segment is that they are like two eyes with a line in the middle (sorry they make the answer 20 or more characters)

You might be interested in

At 30 miles an hour how long does it take to travel 180 miles from

Archy [21]

60 min in an hour right? 30 miles means 1 hr. 180/30 = 6. 6 is the number of hr it took to travel 180 miles. make sense?

8 0

3 years ago

The area of a rectangular living room is 264 square feet. The length of the room is 2 feet less than twice the width.

Sidana [21]

9514 1404 393

Answer:

12 ft

Step-by-step explanation:

Let the width of the room be represented by w. Then the length is (2w-2), and the area is ...

A = LW

264 = (2w-2)w

132 = w² -w . . . . . . . divide by 2, eliminate parentheses

132.25 = w² -w +.25 . . . . . add (-1/2)² to complete the square

√132.25 = w -0.5 . . . . . take the square root

0.5 +11.5 = w = 12 . . . . . add 0.5; use the positive root

The width of the living room is 12 feet.

5 0

3 years ago

1. (5.1.8) An article reports that in a sample of 132 hip surgeries of a certain type, the average surgery time was 136.9 minute

olganol [36]

Answer:

a) The 95% CI for the mean surgery time is (133.05, 140.75).

b) The 99.5% CI for the mean surgery time is (131.37, 142.43).

c) The level of confidence of the interval (133.9, 139.9) is 69%.

d) The sample size should be 219 surgeries.

e) The sample size should be 377 surgeries.

Step-by-step explanation:

We have a sample, of size n=132, for which the mean time was 136.9 minutes with a standard deviation of 22.6 minutes.

a) We have to find a 95% CI for the mean surgery time.

The critical value of z for a 95% CI is z=1.96.

The margin of error of the CI can be calculated as:

$E=z\cdot s/\sqrt{n}=1.96*22.6/\sqrt{132}=44.296/11.489=3.85$

Then, the lower and upper bounds of the confidence interval are:

$LL=\bar x-E=136.9-3.85=133.05\\\\UL=\bar x+E=136.9+3.85=140.75$

The 95% CI for the mean surgery time is (133.05, 140.75).

b) Now, we have to find a 99.5% CI for the mean surgery time.

The critical value of z for a 99.5% CI is z=2.81.

The margin of error of the CI can be calculated as:

$E=z\cdot s/\sqrt{n}=2.81*22.6/\sqrt{132}=63.506/11.489=5.53$

Then, the lower and upper bounds of the confidence interval are:

$LL=\bar x-E=136.9-5.53=131.37\\\\UL=\bar x+E=136.9+5.53=142.43$

The 99.5% CI for the mean surgery time is (131.37, 142.43).

c) We can calculate the level of confidence, calculating the z-score for the margin of error in that interval.

We know that the difference between the upper bound and lower bound is 2 times the margin of error:

$UL-LL=2E\\\\E=\dfrac{UL-LL}{2}=\dfrac{139.9-133.9}{2}=\dfrac{6}{2}=3$

Then, we can write the equation for the margin of error to know the z-value.

$E=z \cdot s/\sqrt{n}\\\\z= E\cdot \sqrt{n}/s=2*\sqrt{132}/22.6=2*11.5/22.6=1.018$

The confidence level for this interval is then equal to the probability that the absolute value of z is bigger than 1.018:

$P(-|z|$

The level of confidence of the interval (133.9, 139.9) is 69%.

d) We have to calculate the sample size n to have a margin of error, for a 95% CI, that is equal to 3.

The critical value for a 95% CI is z=1.96.

Then, the sample size can be calculated as:

$E=z\cdot s/\sqrt{n}\\\\n=(\dfrac{z\cdot s}{E})^2=(\dfrac{1.96*22.6}{3})^2=14.77^2=218.015\approx 219$

The sample size should be 219 surgeries.

e) We have to calculate the sample size n to have a margin of error, for a 99% CI, that is equal to 3.

The critical value for a 99% CI is z=2.576.

Then, the sample size can be calculated as:

$E=z\cdot s/\sqrt{n}\\\\n=(\dfrac{z\cdot s}{E})^2=(\dfrac{1.96*22.6}{3})^2=19.41^2=376.59\approx 377$

The sample size should be 377 surgeries.

6 0

4 years ago

What is the total surface area of the square pyramid?

pochemuha

Answer:

Step-by-step explanation:

The square pyramid has exactly the same four triangles.

In order to find the whole surface area, we must find the area of one of the triangles and multiply them by 4.

Surface area of square pyramid = $\frac{bh}{2} * 4$

Where we know that b = 4 and h = 6.

Substituting into the formula should give us the answer 48.

7 0

3 years ago

What is the area of the composite figure?

Rudik [331]

I have uploaded a link! The answer is in the link below:

http://www.vegetablefacts.net/vegetable-history/history-of-butthole/

4 0

3 years ago