The sum of the deviations about the mean always equals ________

W-4y+z=0 for z (please show work)

aalyn [17]

Answer: z=-w+4y

Step-by-step explanation:

W-4y+z=0

Calculate product

w-4y+z+0

Move variables to the right

8 0

2 years ago

Where does the decimal go in 288

andreev551 [17]

Answer:

well if you mean 288 as a decimal, it would be 2.88

Step-by-step explanation:

7 0

3 years ago

Sulfur compounds cause "off-odors" in wine, so winemakers want to know the odor threshold, the lowest concentration of a compoun

sladkih [1.3K]

Answer:

a) If we construct a stemplot for the data we have this:

Stem Leaf

1 | 9

2 | 2 3 9

3 | 0 0 1 3 5

4 | 2

Notation: 1|9 means 19

b) $29.4-2.26\frac{6.75}{\sqrt{10}}=24.58$

$29.4-2.26\frac{6.75}{\sqrt{10}}=34.22$

So on this case the 95% confidence interval would be given by (24.58;34.22)

Step-by-step explanation:

For this case we have the following data:

30 30 42 35 22 33 31 29 19 23

Part a

If we construct a stemplot for the data we have this:

Stem Leaf

1 | 9

2 | 2 3 9

3 | 0 0 1 3 5

4 | 2

Notation: 1|9 means 19

As we can see the distribution is a little assymetrical to the right since we have not to much values on the right tail. But we can approximate roughly the distribution symmetric and with no outliers.

Part b

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".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=29.4$

The sample deviation calculated $s=6.75$

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=10-1=9$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,9)".And we see that $t_{\alpha/2}=2.26$

Now we have everything in order to replace into formula (1):

$29.4-2.26\frac{6.75}{\sqrt{10}}=24.58$

$29.4-2.26\frac{6.75}{\sqrt{10}}=34.22$

So on this case the 95% confidence interval would be given by (24.58;34.22)

8 0

2 years ago

Five friends agree to save money for a graduation road trip. They decide that

nydimaria [60]

Answer:

$620

Step-by-step explanation:

First you have to figure out the amount one of them would add which is $124. You would do this by adding .25+.50+.75+1 ect. Then once you know how much one of them would add you do 124(5) and get $620.

5 0

3 years ago

A 2-quart carton of sour cream costs $4.32. What is the price per cup?

damaskus [11]

Answer:

0.54 cents

Step-by-step explanation:

4 cups per quart = 8 cups per 2 quarts

4.32/8 = .54

6 0

2 years ago

The sum of the deviations about the mean always equals _________.