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2 years ago

Determine the sign of cos pi divided by seven without using a calculator.

Mathematics

1 answer:

7nadin3 [17]2 years ago

3 0

Check the picture below.

now, when you get a fraction of π for the angle, is just really like grabbing π and dividing it in that many pieces, and the angle, is a fraction of π and therefore on those pieces.

π/7 is clearly less than 7π/7 which is π, notice the 7-pieces split in the picture.

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I need help please !!!

juin [17]

Answer:

f = 12(s - 35).

Step-by-step explanation:

The number of miles per hour he was over the limit = s - 35.

So his fine f is:

f = 12(s - 35).

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3 years ago

1. The temperature of a body rises from -6°c to 5°c. By how much degrees does it rises? <br>

babunello [35]

It rises 11 degrees

Step by step explanation

3 0

2 years ago

At a university, 12% of students smoke. Calculate the expected number of smokers in a random sample of 140 students from this un

Masteriza [31]

Answer:

a) The expected number of smokers in a random sample of 140 students from this university is 16.8 smokers.

b) No, it is unlikely that smoking habits and waking up early to go to the gym on Saturday are independent.

Step-by-step explanation:

To calculate the expected numbers of smokers in a sample with size n=140 and proportion p=12%, we use the expected value of the binomial distribution:

$E(x)=n\cdot p=140\cdot 0.12=16.8$

The expected number of smokers in a random sample of 140 students from this university is 16.8 smokers.

If we take a sample at the opening of the gym, the sample is not expected to be representative of the population of the students. Most of the students that go to the gym usually have healthy habits, so the proportions of smokers is expected to be lower than the average of the university population.

4 0

2 years ago

Q. A customer wants to re-carpet a living room andhallway. You charge $5.99 per square yard toremove old carpet and $4.50 per sq

Tanzania [10]

Living Room Area = 17.5 x 20 = 350 sq ft

Hall Area = 4 x 12 = 48 sq. ft.

Total area of carpeting: 340 + 48 = 398 sq. ft.

We need to convert total area in sq ft to sq yd. The conversion ratio is

1 sq ft = 0.11 sq yd

So, 398 sq ft would be:

398 * 0.11 = 44.22 sq yd.

Carpet removing rate is 5.99 per sq yd.

Removing rate would be:

44.22 * 5.99 = $264.88

Assuming you gotta install both carpet and pad,

Carpet + pad = 16.99 + 3 = 19.99 per sq yd.

You gotta buy for 44.22 sq yd.

So, it will cost (carpet):

44.22 * 19.99 = $883.96

Installing rate 4.50 per sq yrd, so to carpet 44.22 sq yd, would need:

4.50*44.22 = $198.99

Assuming carpet is provided by installation guys, total charge:

4 0

9 months ago

Persons taking a 30-hour review course to prepare for a standardized exam average a score of 620 on that exam. Persons taking a

Alina [70]

Given:

30-hour review course average a score of 620 on that exam.

70-hour review course average a score of 749.

To find:

The linear equation which fits this data, and use this equation to predict an average score for persons taking a 57-hour review course.

Solution:

Let x be the number of hours of review course and y be the average score on that exam.

30-hour review course average a score of 620 on that exam. So, the linear function passes through the point (30,620).

70-hour review course average a score of 749. So, the linear function passes through the point (70,749).

The linear function passes through the points (30,620) and (70,749). So, the linear equation is:

$y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)$

$y-620=\dfrac{749-620}{70-30}(x-30)$

$y-620=\dfrac{129}{40}(x-30)$

$y-620=\dfrac{129}{40}(x)-\dfrac{129}{40}(30)$

$y-620=\dfrac{129}{40}(x)-\dfrac{387}{4}$

Adding 620 on both sides, we get

$y=\dfrac{129}{40}x-\dfrac{387}{4}+620$

$y=\dfrac{129}{40}x+\dfrac{2480-387}{4}$

$y=\dfrac{129}{40}x+\dfrac{2093}{4}$

We need to find the y-value for $x=57$ .

$y=\dfrac{129}{40}(57)+\dfrac{2093}{4}$

$y=183.825+523.25$

$y=707.075$

$y\approx 707.1$

Therefore, the required linear equation for the given situation is $y=\dfrac{129}{40}x+\dfrac{2093}{4}$ and the average score for persons taking a 57-hour review course is 707.1.

4 0

2 years ago