Select all the solutions for the quadratic equation x2=81 . Answer Choices x=9 x=81 x=−9 x=−81

Alex then paint the face of the clock with white paint it has a diameter of 14 inches what is the area of the clock face

suter [353]

The area of the clock is 153.86(preferred)/153.94 or 49n n=pi

14/2 is 7 7*7=49 49 x pi is 153.94

3 0

4 years ago

2. Create an estimated probability distribution for the time teens spend texting.

Furkat [3]

Answer:

Hours 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Frequency* 0.2 0.09 0.25 0.18 0.11 0.07 0.05 0.02 0.01 0.02 0.01

Problem Statement:

The table shows the number of hours, to the nearest half hour per day, that teens spend texting according to a random sample of 870 teenagers aged 13–18 in a large urban city.

Hours 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Frequency 170 82 220 153 92 58 40 15 12 18 10

Step-By-Step Explanation:

As we need the estimated probability distribution for teens spending time texting, we will be needing the total sample size.

As given in the problem statement,

Total Sample Size = 870

To calculate estimated probability distribution, we will convert the frequency sample into estimated probability distribution, for that:

Estimated Probability Distribution (Frequency*)= $\frac{Frequency.Sample.Size.of.that.hour}{Total.Sample.Size}$

For Example:

Estimated probability distribution that teens spend 0 hours texting= $\frac{170}{870} =0.20$

Similarly

Estimated probability distribution that teens spend 0.5 hours= $\frac{82}{870} =0.09$

Using the same formula we get:

Hours 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Frequency* 0.2 0.09 0.25 0.18 0.11 0.07 0.05 0.02 0.01 0.02 0.01

(Note: Frequency* is the estimated probability distribution)

4 0

3 years ago

Read 2 more answers

Number 7 and 8 plz answer quickly

Flauer [41]

(7) m∠A = 52°

(8) m∠B = 117°

Solution:

(7) Let us first define the supplementary and complementary angles.

Supplementary angles: Two angles are said to be supplementary angles if their sum is add up to 180°

Complementary angles: Two angles are said to be complementary angles if their sum is add up to 90°

Given supplement of 142° = 180° – 142°

= 38°

Complement of ∠A = Supplement of 142°

⇒ Complement of ∠A = 38°

Measure of ∠A = 90° – 38°

= 52°

Hence m∠A = 52°.

(8) Given complement of 27° = 90° – 27°

= 63°

Supplement of ∠B = Complement of 27°

⇒ Supplement of ∠B = 63°

Measure of ∠B = 180° – 63°

= 117°

Hence m∠B = 117°.

3 0

4 years ago

A tire has a radius of 12 in. If that tire makes one full rotation how far does it travel?

mrs_skeptik [129]

5 rotations
Hope this helps

4 0

3 years ago

). If a, ß are zeroes of the quadratic polynomial p(x)=kx²+4x+4 such

natta225 [31]

Answer:

The values of k are 2/3 and -1

Step-by-step explanation:

Product of zeros = αβ= constant / coefficient of x^2 = 4/k

Sum of zeros =α+β = - coefficient of x / coefficient of x^2= -4/k

Given

Consider a= α and b= β

$(\alpha)^2 + (\beta)^2 = 24$

$(\alpha)^2 + (\beta)^2$ can be written as $(\alpha)^2 + 2(\alpha)(\beta) + (\beta)^2$ if we add $\pm 2 (\alpha)(\beta)$ in the above equation.

$(\alpha)^2 + 2(\alpha)(\beta) + (\beta)^2 -2(\alpha)(\beta)$

$(\alpha + \beta)^2 -2(\alpha)(\beta)$

Putting values of αβ and α+β

$(\frac {-4}{k})^2 -2( \frac {4}{k}) = 24\\\frac {16}{k^2} - \frac {8}{k} = 24\\Multiplying\,\, the \,\, equation\,\, with\,\, 8K^2\\ 2 - k= 3K^2\\3k^2-2+k=0\\or\\3k^2+k-2=0\\3k^2+3k-2k-2=0\\3k(k+1)-2(k+1)=0\\(3k-2)(k+1)=0\\3k-2=0 \,\,and\,\, k+1 =0\\k= 2/3 \,\,and\,\, k=-1$

The values of k are 2/3 and -1

8 0

4 years ago