An instructional video is 7.8 minutes long is the video in second ? how long is it in hours?

Which expression is equivalent to n+n+n? A. 3^n B. 3n C. n^3 D. n+3

Irina18 [472]

Answer:

B. 3n

Step-by-step explanation:

n + n + n = 3n

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3n = n + n + n

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5 0

2 years ago

Zack, Rachel, and Maddie are unraveling a huge ball of yarn to see how long it is. As they move away from each other, they form

Korolek [52]

We are tasked to solve the three angles given that we have the measurements of the sides such as
a = Zack to Rachel distance
b = Rachel to Maddie distance
c = Maddie to Zack distance

a =3
b =2.5
c =4

Solving the angles we need to use Law of Cosines:
cos A = 2.5² + 4² -3² /2*2.5*4
A = 48.59°

cos B=3² + 4² - 2.5² / 2*3*4
B = 38.625°

C=180 - 48.59° - 38.625°
C= 92.79°

The three angles are 48.59°,38.63° and 92.79°.

8 0

4 years ago

If 12% of the air leaks out of Brian's bicycle tire every day, what percent of the air will be left after 2 days? After a week?

Leni [432]

Answer:

77.44%

49.87%

Step-by-step explanation:

If 12% leaks everyday, on the first day 12% would leak, leaving 100 - 125 = 88% of air

on the second day, 12% of 88% would leak = 0.88 x 0.12 = 0.1056

Air left on the second day = 88% - 10.56% = 77.44%

After a week = (100 - 12%)^7 = 49.87%

6 0

3 years ago

Find the geometric mean between 9 and 11

klio [65]

Step-by-step explanation:

Geometric mean is the square root of the product.

√(9 × 11) = √99 ≈ 9.950

3 0

3 years ago

Almost all medical schools in the United States require students to take the Medical College Admission Test (MCAT). To estimate

yKpoI14uk [10]

Answer:

a) 0.5588

b) 0.9984

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 24

Standard Deviation, σ = 6.4

We are given that the distribution of score is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

a) P(score between 20 and 30)

$P(20 \leq x \leq 30) = P(\displaystyle\frac{20 - 24}{6.4} \leq z \leq \displaystyle\frac{30-24}{6.4}) = P(-0.62 \leq z \leq 0.94)\\\\= P(z \leq 0.94) - P(z < -0.62)\\= 0.8264 - 0.2676 = 0.5588 = 55.88\%$

$P(20 \leq x \leq 30) = 55.88\%$

b) Sampling distribution

Sample size, n = 22

The sample will follow a normal distribution with mean 24 and standard deviation,

$s = \dfrac{\sigma}{\sqrt{n}} = \dfrac{6.4}{\sqrt{22}} =1.36$

c) P(mean score of sample is between 20 and 30)

$P(20 \leq x \leq 30) = P(\displaystyle\frac{20 - 24}{1.36} \leq z \leq \displaystyle\frac{30-24}{1.36}) = P(-2.94 \leq z \leq 4.41)\\\\= P(z \leq 4.41) - P(z < -2.94)\\= 1 - 0.0016 = 0.9984 = 99.84\%$

$P(20 \leq x \leq 30) =99.84\%$

5 0

3 years ago