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3 years ago

What is the difference? Complete the equation. -4 - 2 1/2

Mathematics

1 answer:

Lina20 [59]3 years ago

5 0

Answer: - 6 1/2

Step-by-step explanation:

We should note that:

=-4 - 2 1/2

= -6 1/2

For example, let's assume you owe Bob $4 and then you owe Bill $2 1/2. To calculate the total amount owed, you would have $6 1/2.

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Please help me asap i will mark branlist please explain

Ulleksa [173]

It would be b because a^2+b^2=c^2 so in this case 5^2+8^2=c^2

6 0

3 years ago

According to a recent survey, the population distribution of number of years of education for self-employed individuals in a c

creativ13 [48]

Answer:

a) X: number of years of education

b) Sample mean = 13.5, Sample standard deviation = 0.4

c) Sample mean = 13.5, Sample standard deviation = 0.2

d) Decrease the sample standard deviation

Step-by-step explanation:

We are given the following in the question:

Mean, μ = 13.5 years

Standard deviation,σ = 2.8 years

a) random variable X

X: number of years of education

Central limit theorem:

If large random samples are drawn from population with mean $\mu$ and standard deviation $\sigma$ , then the distribution of sample mean will be normally distributed with mean $\mu$ and standard deviation $\frac{\sigma}{\sqrt{n}}$

b) mean and the standard for a random sample of size 49

$\mu_{\bar{x}} = \mu = 13.5\\\\\sigma_{\bar{x}} = \dfrac{\sigma}{\sqrt{n}} = \dfrac{2.8}{\sqrt{49}} = 0.4$

c) mean and the standard for a random sample of size 196

$\mu_{\bar{x}} = \mu = 13.5\\\\\sigma_{\bar{x}} = \dfrac{\sigma}{\sqrt{n}} = \dfrac{2.8}{\sqrt{196}} = 0.2$

d) Effect of increasing n

As the sample size increases, the standard error that is the sample standard deviation decreases. Thus, quadrupling sample size will half the standard deviation.

7 0

3 years ago

What is the sum to this equation ?pl

SVEN [57.7K]

The answer is 15/10.

5 0

3 years ago

Read 2 more answers

Jill bought a lamp for $40. She sold it at a garage sale for $12. What was the approximate decrease?

Vesnalui [34]

Answer:

she was left with 28$ I'm in high school i think I'm right

Step-by-step explanation:

3 0

3 years ago

Bill and Mary Ann went to the Viola bakery. Bill bought 3 danishes and 8 filled donuts for $14.67. Mary Ann bought 7 of each fo

harina [27]

Answer:

donuts cost $1.5

danishes cost $1.57

Step-by-step explanation:

This is a typical 2-equation syestem with 2 unknown variables problem. Lets find out which are our equations and unknowns.

Bill ought 3 danishes and 8 filled donuts for $14.67. Lets call d the price of donuts and c the price of danishes. We can then write Bill expenditures as an equation (I will omit $ symbol for simplicity):

3 c + 8 d = 14.67 [eq 1]

Now we can do the same for Mary's expenditures, as she bought 7 of each for $16.73:

7 c + 7 d = 16.73 [eq. 2]

Now, lets take eq. 1 and try to get the value of one of the variables, for example c, as function of the other -in this case, d. Notice you could also do this with eq. 2.

So:

3 c + 8 d = 14.67

Subtract 8d in both sides:

3c = 14.67 - 8d

Now, divide both sides by 3:

c = (14.67 - 8d)/3

So, we have c in function of d. Now, replace this value in eq 2:

7*(14.67 - 8d)/3 + 7 d = 16.73

(7/3)*(14.67 - 8d) + 7d = 16.73

Applying distributive:

(7/3)*14.67 - (7/3)*8d + 7d = 16.73

34.23 - 18.67d + 7d = 16.73

34.23 - 11.67d = 16.73

Now, subtract 34.23 in both sides:

-11.67 d = -17.5

Dividing both sides by -11.67

d = 1.50

So, every donuts costs $1.5. If we replace this value in any of the equations of the system we get c. Lets replace in eq. 1:

3 c + 8 d = 14.67

3 c + 8*1.5 = 3c + 12 = 14.67

Subtract 12 in both sides:

3c = 4.67

Divide by 3 in both sides:

c = 1.57

Important: notice that the results may variate in some decimals or less depending on how many numbers after the coma you use. For example, d is really 1.49957155098543 but I used 1.50, if you are more precise and use 1.49957 you results may variate a little but not significantly.

So, c=1.57 and d=1.50 is the solution. A donuts cost $1.5 and a danish $1.57.

5 0

3 years ago

Read 2 more answers