Pleaseeeee Helpppppp me

2 trig ratios missing sides and angels

ivanzaharov [21]

Answer:

D

Step-by-step explanation:

Using the cosine ratio in the right triangle.

cos66° = $\frac{adjacent}{hypotenuse}$ = $\frac{13}{x}$ ( multiply both sides by x )

x × cos66° = 13 ( divide both sides by cos66° )

x = $\frac{13}{cos66}$ ≈ 32.0 ( to the nearest tenth )

8 0

3 years ago

An instructor in a college class recently gave an exam that was worth a total of 100 points. The instructor inadvertently made t

solniwko [45]

Answer:

B) Method 2 will increase the standard deviation of the students' scores.

Step-by-step explanation:

Given that an instructor in a college class recently gave an exam that was worth a total of 100 points.

The average score for his students was 43 and the standard deviation of the scores was 5 points.

And now he is considering two different strategies for rescaling the exam results of which:

Method 1 = Add 17 points to everyone's score.

Method 2 = Multiply everyone's score by 1.7 .

And we have to check what will be the impact of these methods on the standard deviation of the students' scores.

For this let us consider a simple example to understand this:

Firstly, Formula for calculating Standard Deviation = $\sqrt{\frac{\sum (X-Xbar)^{2}}{n-1}}$

Suppose,

X X - Xbar $(X - Xbar)^{2}$

3 3 - 6 = -3 -3 * -3 = 9

5 5 - 6 = -1 -1 * -1 = 1

10 10 - 6 = 4 4 * 4 = 16

Mean of above data, Xbar = $\frac{3+ 5+10}{3}$ = 6

Standard Deviation of data = $\sqrt{\frac{26}{3-1} }$ = 3.6055

Now let us suppose that we multiply each value of above data with 2 so the new data will be:

X X - Xbar $(X - Xbar)^{2}$

3*2 = 6 6 - 12 = -6 -6 * -6 = 36

5*2 = 10 10 - 12 = -2 -2 * -2 = 4

10*2 =20 20 - 12 = 8 8 * 8 = 64

Mean of new data, Xbar = $\frac{6+ 10+20}{3}$ = 12

Standard Deviation of new data = $\sqrt{\frac{104}{3-1} }$ = 7.2111

Hence, we see that when we multiply any value to the data the standard deviation will increase and in other words it will multiplied by that value which value we multiplied with each data value i.e. when we multiply each data value with 2 the standard deviation also get multiplied by as

3.6055 * 2 = 7.2111

Therefore option B is correct that Method 2 will increase the standard deviation of the students' scores.

And on the other hand Similarly by adding any constant to the data the Standard Deviation will remain same. Therefore Method 1 will have no impact on standard deviation of the students' scores.

8 0

3 years ago

Help!! I need to answer this question.

babunello [35]

"AC/DF = 5/2" is correct.

8 0

3 years ago

5. HELP ASAP!!! GIVING BRAINLIEST!!! Find each missing measure.

Sladkaya [172]

Answer:

x = 6

Sorry if this answer is not correct, if it is or is not, please tell me in the comments!

Step-by-step explanation:

All of the angles add up to 180 degrees (since it is a triangle), so

(11x - 3) + (7x + 5) + (13x - 8) = 180

Then, combine the like terms.

31x - 6 = 180

Now, out goal is to separate the x from everything. To do that, we need to add 6 to 180.

31x = 186

Then divide by 31.

x = 6

(Feel free to replace x with 6 back in the previous equation to double check it!)

4 0

2 years ago

Read 2 more answers

R + 4 > 8; r =2 is a solution

tiny-mole [99]

Answer:r>4

Step-by-step explanation: You just subtract four from both sides

7 0

4 years ago