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3 years ago

Please can someone help!

Mathematics

2 answers:

KIM [24]3 years ago

6 0

Answer:

Charles: 17 points

Adam: 25 points

Bethany: 30 points

stira [4]3 years ago

6 0

Answer:

Adam scored 25 points.

Bethany scored 30 points.

Charles scored 17 points.

Step-by-step explanation:

A = Adam, B = Bethany, C = Charles

What we know:

C + 8 = A

A + 5 = B

A + B + C = 72

Charles:

C + 8 + 5 = B

C + (C + 8) + (C + 13) = 72

72 - 8 - 13 = 51

51/3 = 17

Charles scored 17 points.

Bethany:

17 + 13 = 30

Bethany scored 30 points.

Adam:

17 + 8 = 25

Adam scored 25 points.

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3 years ago

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Anettt [7]

Answer:

Choice C: approximately 121 green beans will be 13 centimeters or shorter.

Step-by-step explanation:

What's the probability that a green bean from this sale is shorter than 13 centimeters?

Let the length of a green bean be $X$ centimeters.

$X$ follows a normal distribution with

mean $\mu = 11.2$ and
standard deviation $\sigma = 2.1$ .

In other words,

$X\sim \text{N}(11.2, 2.1^{2})$ ,

and the probability in question is $X \le 13$ .

Z-score table approach:

Find the z-score of this measurement:

$\displaystyle z= \frac{x-\mu}{\sigma} = \frac{13-11.2}{2.1} = 0.857143$ . Closest to 0.86.

Look up the z-score in a table. Keep in mind that entries on a typical z-score table gives the probability of the left tail, which is the chance that $Z$ will be less than or equal to the z-score in question. (In case the question is asking for the probability that $Z$ is greater than the z-score, subtract the value from table from 1.)

$P(X\le 13) = P(Z \le 0.857143) \approx 0.8051$ .

"Technology" Approach

Depending on the manufacturer, the steps generally include:

Locate the cumulative probability function (cdf) for normal distributions.
Enter the lower and upper bound. The lower bound shall be a very negative number such as $-10^{9}$ . For the upper bound, enter $13$
Enter the mean and standard deviation (or variance if required).
Evaluate.

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As a result,

$P(X\le 13) = 0.804317$ .

Number of green beans that are shorter than 13 centimeters:

Assume that the length of green beans for sale are independent of each other. The probability that each green bean is shorter than 13 centimeters is constant. As a result, the number of green beans out of 150 that are shorter than 13 centimeters follow a binomial distribution.

Number of trials $n$ : 150.
Probability of success $p$ : 0.804317.

Let $Y$ be the number of green beans out of this 150 that are shorter than 13 centimeters. $Y\sim\text{B}(150,0.804317)$ .

The expected value of a binomial random variable is the product of the number of trials and the probability of success on each trial. In other words,

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3 years ago

The distance between the cities Chicago and Toronto is 540 miles. A motorcycle's speed is 48 mph. For a car, it takes 2.25 hours

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Answer:

5 hours

Step-by-step explanation:

given :

Distance between the cities = 540 miles

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By putting given values in the formula we get :

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Thus , Time taken by car to cover the same distance is 9 hours .

Now to calculate speed of car by using formula:

$\frac{distance}{time}$

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= 60 mph

Let t be the time taken to meet if they start moving towards each other.

So distance covered by motorcycle in t hours is

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Distance covered by car in t hours is

speed\times time

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