Data collected from a survey of American teenagers aged 13 to 17 was used to estimate that 29% of teens believe in ghosts. This estimate was based on data from 510 American teenagers. What is the population that people carrying out the survey were interested in?

Solved

Show answers

Ответ:

melody32

01.12.2021

Mathematics

Given:

Consider the below figure attaches with this question.

To find:

The size of angle x.

Solution:

Law of Cosines:

$\cos A=\dfrac{b^2+c^2-a^2}{2bc}$

Three sides of the triangle are 11 cm, 8 cm, 15 cm. Since 11 cm is the opposite side of the angle x, therefore a=11 .

Let A=x,a=11,b=8,c=15 . Substitute these values in the above formula.

$\cos x=\dfrac{8^2+15^2-11^2}{2(8)(15)}$

$\cos x=\dfrac{64+225-121}{240}$

$\cos x=\dfrac{168}{240}$

$\cos x=0.7$

Taking cos inverse on both sides, we get

$x=\cos^{-1} 0.7$

$x=45.572996^\circ$

$x\approx 45.6^\circ$

Therefore, the measure of angle x is 45.6°.

Calculate the size of angle x.

Give your answer to 1 decimal place.
8 cm
11 cm
х
15 cm

0,0(0 оценок)

Ask your question to the AI advisor

Ai-bot is an expert in any field and is the perfect companion for reliable and useful answers and advice on a variety of topics, including science, history, technology, art, sports, health, culture and more.

Ask your question

More tips

Answers on questions: Mathematics

Ask an AI advisor a question

I want advice