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2 years ago

HELP I’VE FALLEN AND I️ CANT GET UP! (jk) I️ JUST REALLY NEED HELP ON THIS ALGEBRA QUESTION?!

Mathematics

1 answer:

Lana71 [14]2 years ago

3 0

use cross products

(3r+6) *2 = 9*(2r-4)

6r+12 = 18r-36 distribute

12 = 12 r -36 subtract 6r from each side

48 = 12r add 36 to each side

4=r divide by 12

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6. Michael Johnson holds the Olympic record for the men's 400m race at 43 seconds. His

vlada-n [284]

The difference between both unit rates rounded off to the nearest tenth is: 0.4 meters per second

Step-by-step explanation:

We have to calculate his unit rate for both type of races

So,

Distance = 400m

Time = 43 sec

$Unit\ rate = U_1= \frac{Distance}{Time}\\=\frac{400}{43}\\=9.30\ meters\ per\ second$

Distance = 300m

Time = 31 sec

$Unit\ Rate= U_2=\frac{300}{31}\\=9.68\ meters\ per\ second$

The difference between both unit rates is:

$U_2-U_1 = 9.68-9.30\\=0.38 => 0.4\ meters\ per\ sec$

Hence,

The difference between both unit rates rounded off to the nearest tenth is: 0.4 meters per second

Keywords: Unit rate, Speed

Learn more about unit rate at:

#LearnwithBrainly

7 0

2 years ago

According to a recent study of 7335 young people in the US, 30% had been arrested for a crime other than a traffic violation by

victus00 [196]

Answer:

a) Statistic.

b) The population proportion is expected to be between 0.29 and 0.31 with a 94% degree of confidence.

Step-by-step explanation:

a) The proportion of 30% is a statistic, as it is a value that summarizes data only from the sample taken in the study from USA Today. Other samples may yield different proportions.

b) We can use the statistic to estimate a confidence interval for the parameter of the population.

The standard error for the proportion is calculated as:

$\sigma_p=\sqrt{\dfrac{p(1-p)}{N}}=\sqrt{\dfrac{0.3\cdot 0.7}{7335}}=\sqrt{2.83\cdot10^5}= 0.00535$

The margin of error is 0.01. We can use this value to determine the level of confidence that represents.

The formula for the margin of error is:

$E=z\cdot \sigma_p=0.01\\\\z\cdot 0.0535=0.01\\\\z=1.87$

This z-value, according to the the standard normal distribution, corresponds to a confidence interval of 94%.

The interval for this margin of error is:

$p-E\leq \pi \leq p+E\\\\0.30-0.01\leq \pi \leq 0.30+0.01\\\\0.29\leq \pi \leq 0.31$

Then, we can conclude that the population proportion is expected to be between 0.29 and 0.31 with a 94% degree of confidence.

3 0

3 years ago

Mum is 25 years older than her son Max, but she is 1 year younger than

In-s [12.5K]

Answer:

Step-by-step explanation:

8 0

2 years ago

Suppose the force acting on a column that helps to support a building is a normally distributed random variable X with mean valu

Sauron [17]

Answer:

(1) 0.4207

(2) 0.7799

Step-by-step explanation:

Given,

Mean value,

$\mu = 15.0$

Standard deviation,

$\sigma = 1.25$

(1) P(X ≥ 17.5) = 1 - P( X ≤ 17.5)

$= 1- P(\frac{x-\mu}{\sigma} \leq \frac{17.5-\mu}{\sigma})$

$=1-P(z\leq \frac{17.5 - 15}{1.25})$

$=1-P(z\leq \frac{2.5}{1.25})$

$=1-P(z\leq 2)$

$=1- 0.5793$ ( By using z-score table )

= 0.4207

(2) P(14 ≤ X ≤ 18) = P(X ≤ 18) - P(X ≤ 14)

$=P(z\leq \frac{18 - 15}{1.25}) - P(z\leq \frac{14 - 15}{1.25})$

$=P(z\leq \frac{3}{1.25}) - P(z\leq -\frac{1}{1.25})$

$=P(z\leq 2.4) - P(z\leq -0.8)$

= 0.9918 - 0.2119

= 0.7799

8 0

2 years ago

Here are some point to help with your difficulties Hope you have a good day :)

Arlecino [84]

Answer:thanks

Step-by-step explanation:

8 0

2 years ago

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