M.

The calculated average of a data set best describes which of the following

sasho [114]

The calculated average of a data set best describes A: Mean.

3 0

3 years ago

MN is the midsegment of the trapezoid ABCD. What is the length of segment AB?

vladimir1956 [14]

Dear Student,

Answer to your query is provided below:

The length of segment AB = 8

Explanation to answer is provided by attaching image.

8 0

3 years ago

How would you describe your ability to solve equations with two or more steps

dexar [7]

I would describe it as talented and accurate. I have not gotten anything lower than a b+ in any of my classes, including math.

3 0

3 years ago

Please help me I don’t know what to do

Lisa [10]

Answer:

(x-3,y-4) = correct

Step-by-step explanation:

5 0

2 years ago

A random sample of 20 students yielded a mean of ¯x = 72 and a variance of s2 = 16 for scores on a college placement test in mat

Helen [10]

Answer:

The 98% confidence interval for the variance in the pounds of impurities would be $8.400 \leq \sigma^2 \leq 39.827$ .

Step-by-step explanation:

1) Data given and notation

$s^2 =16$ represent the sample variance

s=4 represent the sample standard deviation

$\bar x$ represent the sample mean

n=20 the sample size

Confidence=98% or 0.98

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 mean or variance 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.

The Chi square distribution is the distribution of the sum of squared standard normal deviates .

2) Calculating the confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

On this case the sample variance is given and for the sample deviation is just the square root of the sample variance.

The next step would be calculate the critical values. First we need to calculate the degrees of freedom given by:

$df=n-1=20-1=19$

Since the Confidence is 0.98 or 98%, the value of $\alpha=0.02$ and $\alpha/2 =0.01$ , and we can use excel, a calculator or a table to find the critical values.