Mr. Webster is buying a carpet for an exercise room in his basement the room will have an area of 230 ft.².

(10 times 2) + 5 times 8 =

DerKrebs [107]

The answer is 60 because 10 x 2 is 20 and 5 x 8 is 40 and add those together to get 60

7 0

2 years ago

Subtract 5-3 1/3 fraction

AleksAgata [21]

5 = 15/3

3 1/3 = 10/3

15/3 - 10/3 = 5/3

so 5-3 1/3 is either 5/3 or 1 2/3.

4 0

3 years ago

Which will equation show correctly we write an expression that represents the cost for a pair of shoes that is marked down 20% o

alukav5142 [94]

Answer:

A

Step-by-step explanation:

You can write an expression to represent the total cost of a pair of shoes. The price of the shoes is the variable r. The shoes are marked down 20% or 0.2r. So the new price of the shoes will be r - 0.2r. You will also have to pay a tax of 5% or 0.05 of the new price. This is written as 1.05(r - 0.2r). You can simplify it by doing whats in the parenthesis.

1.05(r - 0.2r) = 1.05r(0.8r) = 0.84r

4 0

3 years ago

5. Decide if each of the following statements is true or false. Explain your reasoning in each case.

sertanlavr [38]

Answer:

a. The smaller the sample size, the smaller the margin of error.

False if we see the value for the sample size is on the denominator and if we decrease the value of n then increase the value for the margin of error since the margin of error and the sample size are inversely proportional, with the estimated proportion and the confidence level fixed values.

b. If the margin of error is 0.05 and the observed proportion of red chips is 0.45, then the true population proportion is likely to be between 0.40 and 0.50.

Correct. The confidence interval for the population proportion is given by:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

Or equivalently:

$\hat p \pm ME$

And if we replace on this case we got:

$0.45-0.05=0.40$

$0.45 +0.05=0.50$

So then the true proportion is between 0.4 and 0.5 for this case.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Solution to the problem

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

Now if we analyze the statements one by one we have this:

a. The smaller the sample size, the smaller the margin of error.

False if we see the value for the sample size is on the denominator and if we decrease the value of n then increase the value for the margin of error since the margin of error and the sample size are inversely proportional, with the estimated proportion and the confidence level fixed values.

b. If the margin of error is 0.05 and the observed proportion of red chips is 0.45, then the true population proportion is likely to be between 0.40 and 0.50.

Correct. The confidence interval for the population proportion is given by:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

Or equivalently:

$\hat p \pm ME$

And if we replace on this case we got:

$0.45-0.05=0.40$

$0.45 +0.05=0.50$

So then the true proportion is between 0.4 and 0.5 for this case.

4 0

3 years ago

Here are a list of numbers.

Rashid [163]

Step-by-step explanation:

easy by applying formula of range and median

8 0

2 years ago