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3 years ago

R

Mathematics

1 answer:

tia_tia [17]3 years ago

8 0

Answer:

17.4cm

Step-by-step explanation

17) In a triangle ABC, BC=8cm, AC=12cm and angle ABC=120

To get the length of AB, we will use the cosine rule

AB² = BC² + AC² - 2(BC)(AC) cos <ABC

AB² = 8² + 12² - 2(8)(12) cos 120

AB² = 64 + 144 - 192cos12

AB² = 208 - (-96)

AB² = 208 +96

AB² = 208 - (-96)

AB² = 304

AB² = 17.4cm

Hence the length of AB is 17.4cm

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Mr. Green teaches mathematics and his class recently finished a unit on statistics. The student scores on this unit are: 40 47 5

Harrizon [31]

Answer:

Mean = 64.46, Median = 62 and Mode = Bi-modal (50 and 62)

Range of the data is 55.

Step-by-step explanation:

We are given that Mr. Green teaches mathematics and his class recently finished a unit on statistics.

<u>The student scores on this unit are:</u> 40, 47, 50, 50, 50, 54, 56, 56, 60, 60, 62, 62, 62, 63, 65, 70, 70, 72, 76, 77, 80, 85, 85, 95.

We know that Measures of Central Tendency are: Mean, Median and Mode.

Mean is calculated as;

Mean = $\frac{\sum X}{n}$

where $\sum X$ = Sum of all values in the data

n = Number of observations = 24

So, Mean = $\frac{40+ 47+ 50+ 50+ 50+ 54+ 56+ 56+ 60 +60+ 62+ 62+ 62+ 63+ 65+ 70+ 70+ 72+ 76+ 77+ 80+ 85+ 85+ 95}{24}$

= $\frac{1547}{24}$ = 64.46

So, mean of data si 64.46.

For calculating Median, we have to observe that the number of observations (n) is even or odd, i.e.;

If n is odd, then the formula for calculating median is given by;

Median = $(\frac{n+1}{2})^{th} \text{ obs.}$

If n is even, then the formula for calculating median is given by;

Median = $\frac{(\frac{n}{2})^{th}\text{ obs.} +(\frac{n}{2}+1)^{th}\text{ obs.} }{2}$

Now here in our data, the number of observations is even, i.e. n = 24.

So, Median = $\frac{(\frac{n}{2})^{th}\text{ obs.} +(\frac{n}{2}+1)^{th}\text{ obs.} }{2}$

= $\frac{(\frac{24}{2})^{th}\text{ obs.} +(\frac{24}{2}+1)^{th}\text{ obs.} }{2}$

= $\frac{(12)^{th}\text{ obs.} +(13)^{th}\text{ obs.} }{2}$

= $\frac{62 + 62 }{2}$ = $\frac{124}{2}$ = 62

Hence, the median of the data is 62.

A Mode is a value that appears maximum number of times in our data.

In our data, there are two values which appear maximum number of times, i.e. 50 and 62 as these both appear maximum 3 times in the data.

This means our data is Bi-modal with 50 and 62.

The Range is calculated as the difference between the highest and lowest value in the data.

Range = Highest value - Lowest value

= 95 - 40 = 55

Hence, range of the data is 55.

5 0

4 years ago

Which of these could be the value of x in the triangle below

Yuliya22 [10]

The value of x is drawn from the other angles
(There is no triangle for us to look at) so here is a example

Triangle abc has the values as a=23+x° b=x c=69°

All triangles have a combined value of 180°
Now you would have to add the values together and set it equal to 180

23+x+x+69=180
Combine like terms
(69+23)+(x+x) =180
92+x^2=180
Then subtract 92 from 180
Then you have x^2=88
Then you square root the x^2 to make it just x
Then square root 88 because whatever you did to one side has to be done on the other side
X≈ 9.4
- sorry I couldn’t answer your exact question but I hope this explains the steps to solving your exact question

4 0

4 years ago

I need help on number 10 , number 9 and number 11 thank you

Illusion [34]

9.
2(13-p)
2(13-2)=22
2(13-3)= 20
2(13-4)= 18
10.
3v+w
3*4+2=14
3*6+3= 21
3*8+4= 28
11. you cannot see enough to do the problem so what ever the problem is you take the numbers and replace x with them 2 for the first one= x then do the problem to get the answer.

4 0

3 years ago

There are 500 seats on a plane flying to San Francisco. 20% of the seats are next to a window. How many of the seats are next to

Cloud [144]

Answer: 100

500 Is 100%

500 ÷ 100 = 5

5 Is 1%

5 x 20 = 100

100 Is 20%

7 0

3 years ago

Who is good at geometry that can help me?

lina2011 [118]

Answer: d. 3

Step-by-step explanation:

By the The intersecting chords theorem,