Answer -3(-4-6y)+7(-y+5)=-8

the perimeter of a rectangle is 68 cm. the length is 4 cm less than three times ots width. write a system of equation to find th

Gwar [14]

2L + 2w = 68 & L = 3w-4

2(3w-4) = 68

6w-8= 68

6w = 60

W= 10

L = 3*10-4

L= 30-4= 26

6 0

3 years ago

Sally gets a cup of coffee and a muffin every day for breakfast from one of the many coffee shops in her neighborhood. She picks

aniked [119]

Answer:

A. Mean of the amount Sally spends on breakfast daily = $ 3.90

Standard deviation of the amount Sally spends on breakfast daily = $ 0.34 (rounding to the next cent)

B. Mean of the amount Sally spends on breakfast weekly = $ 27.30

Standard deviation of the amount Sally spends on breakfast weekly = $ 0.89 (rounding to the next cent)

Step-by-step explanation:

1. Let's review the information given to us to answer the question correctly:

Average price of a cup of coffee = $ 1.40

Standard deviation = $0.30

Average price of a muffin = $ 2.50

Standard deviation = $ 0.15

The two prices are independent of each other

2. What is the mean and standard deviation of the amount Sally spends on breakfast daily?

Let's recall that:

1. The mean of the sum of two independent variables is the sum of their means.

2. The variance of the sum of two independent variables is equal to the sum of their variances.

Therefore,

Mean of the amount Sally spends on breakfast daily = Average price of a cup of coffee + Average price of a muffin

Replacing with the values we know:

Mean of the amount Sally spends on breakfast daily = 1.40 + 2.50

Mean of the amount Sally spends on breakfast daily = $ 3.90

Variance of the amount Sally spends on breakfast daily = Variance of the price of a cup of coffee + Variance of the price of a muffin

Replacing with the values we know:

Variance of the amount Sally spends on breakfast daily = 0.30² + 0.15²

Variance of the amount Sally spends on breakfast daily = 0.1125

Standard deviation of the amount Sally spends on breakfast daily = √0.1125

Standard deviation of the amount Sally spends on breakfast daily = $ 0.34 (rounding to the next cent)

3. What is the mean and standard deviation of the amount she spends on breakfast weekly (7 days)?

Mean of the amount Sally spends on breakfast weekly = 7 * Mean of the amount Sally spends on breakfast daily

Mean of the amount Sally spends on breakfast weekly = 7 * 3.90

Mean of the amount Sally spends on breakfast weekly = $ 27.30

Variance of the amount Sally spends on breakfast weekly = 7 * Variance of the amount Sally spends on breakfast daily

Variance of the amount Sally spends on breakfast weekly = 7 * 0.1125

Variance of the amount Sally spends on breakfast weekly = 0.7875

Standard deviation of the amount Sally spends on breakfast weekly = √0.7875

Standard deviation of the amount Sally spends on breakfast weekly = $ 0.89 (rounding to the next cent)

3 0

4 years ago

For what value of b, would the equation 3/4(12x−9)+b/4=5−3(2−3x) have infinitely many solutions?

kati45 [8]

Answer:

b=23

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

A shopping channel shipped 467,023 packages last year. What is a reasonable estimate of number of packages shipped?Explain.

kirza4 [7]

470,000 because when you round the number up, you get 470,000. it is reasonable

6 0

3 years ago

Read 2 more answers

What is the probability of choosing a

sladkih [1.3K]

Answer:

Probability of choosing a penny at random is 1/5 or 0.2

Step-by-step explanation:

For many probabilities like this one, you have to add the total of materials or items together, even if they are different colors, shape, coin type, etc.

you have 12 pennies, 19 nickles, 14 dimes, and 15 quarters. This adds up to a total of 60 coins. Twelve of those are pennies.

You have twelve possible pennies to choose at random from a total of 60 in a bag.

So 12/60/ This simplifies to a probability of 1/5. If you divide 1 by 5 than it would be 0.2

The probability of choosing a penny from a bag of coins is 1/5, or 0.2.

Hope this helps

3 0

3 years ago