Given a set {9,3,4,6,x,6,1,-4}, for what x would the mean of the set be -32?

Ricardo Berger
2022-04-25
Answered

Given a set {9,3,4,6,x,6,1,-4}, for what x would the mean of the set be -32?

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drenkttj9

Answered 2022-04-26
Author has **20** answers

Sum of {9,3,4,6,x,6,1,-4} is 25+x

If the mean of these 8 numbers is (-32) then their sum must be:

$(-32)\times 8=-256$

25+x=-256

x=-281

If the mean of these 8 numbers is (-32) then their sum must be:

25+x=-256

x=-281

asked 2022-05-28

Does anyone know what the properties of t-values are?

As I know it's just the ration

$t=\frac{\overline{x}-\mu}{s/\sqrt{n}}$

which follows a t-distribution.

Used in mean-comparison tests and as a consequence also to check the significance of single independent variables in regression analysis. To generalize, t-values are used for hypothesis testing. Am I right with these properties?

Thanks!

As I know it's just the ration

$t=\frac{\overline{x}-\mu}{s/\sqrt{n}}$

which follows a t-distribution.

Used in mean-comparison tests and as a consequence also to check the significance of single independent variables in regression analysis. To generalize, t-values are used for hypothesis testing. Am I right with these properties?

Thanks!

asked 2022-03-18

A survey was conducted to investigate the relationship between gender (male and females) and sector of employment (private, government and academia). Using the information provided, does a relationship exist between gender and employment sector at the 5% significance level? If the Chi-square test statistics = 0.529, what conclusion can be made?

A. Since Chi-square test statistics > Chi-square critical value, do not reject$H}_{0$

B. Since Chi-square test statistics < Chi-square critical value, do not reject$H}_{0$

C. Since Chi-square test statistics < Chi-square critical value, Reject$H}_{0$

D. Since Chi-square test statistics > Chi-square critical value, Reject$H}_{0$

A. Since Chi-square test statistics > Chi-square critical value, do not reject

B. Since Chi-square test statistics < Chi-square critical value, do not reject

C. Since Chi-square test statistics < Chi-square critical value, Reject

D. Since Chi-square test statistics > Chi-square critical value, Reject

asked 2022-03-24

Let $p}_{1$ = population proportion for population 1, $p}_{2$ = population proportion for population 2, ... and $p}_{k$ = population proportion for population k. Consider the following null hypothesis: $H}_{0$ : $p}_{1$ =$p}_{2$ =...=$p}_{k$ . Which of the following statements is correct?

a. The alternative hypothesis to the null hypothesis stated above must be:$H}_{\alpha$ : Not all population proportions are equal.

b. If the sample data and the chi-square test computations indicate$H}_{0$ cannot be rejected, we cannot detect a difference among the k population proportions.

c. If the sample data and the chi-square test computations indicate$H}_{0$ can be rejected, we have the statistical evidence to conclude that one or more population proportions differ from the other population proportions.

d. All of the above.

a. The alternative hypothesis to the null hypothesis stated above must be:

b. If the sample data and the chi-square test computations indicate

c. If the sample data and the chi-square test computations indicate

d. All of the above.

asked 2022-04-03

Statistics finding the confidence level of the interval estimate medical expenses

A confidence interval for the true mean of the annual medical expenses of a middle-class American family is given as (738, 777). If this interval is based on interviews with 110 families and a standard deviation of $ 120 is assumed. Suppose all annual medical expenses of middle-class American families follow an approximately normal distribution.

(a) What is the sample mean of annual medical expenses?

Sample mean$=777+\frac{738}{2}=757.5$

(b) What is the confidence level of the interval estimate (as a decimal)

$CI=\text{sample mean}+z\frac{\alpha}{2}\cdot \left(\frac{\text{standard deviation}}{\text{square root n}}\right)$

Isolate for z$\frac{\alpha}{2}$

$777=757.5+z\frac{\alpha}{2}\cdot \left(\frac{120}{\text{square root}}\text{}110\right)$

Rearrange

$\frac{777\cdot \text{square root}110}{757.5\cdot 120}=z\frac{\alpha}{2}$

$0.089650657=z\frac{\alpha}{2}$

What are the correct solutions and answers?

A confidence interval for the true mean of the annual medical expenses of a middle-class American family is given as (738, 777). If this interval is based on interviews with 110 families and a standard deviation of $ 120 is assumed. Suppose all annual medical expenses of middle-class American families follow an approximately normal distribution.

(a) What is the sample mean of annual medical expenses?

Sample mean

(b) What is the confidence level of the interval estimate (as a decimal)

Isolate for z

Rearrange

What are the correct solutions and answers?

asked 2022-04-23

How to calculate confidence interval for dice hits?

There is a dice with e edges [1;e]. The dice rolls in a one experiment r times. Thus the edge numbered 1 can be generated in this experiment from 0 to r times. I need to calculate theoretical 95% confidence interval for this count.

There is a dice with e edges [1;e]. The dice rolls in a one experiment r times. Thus the edge numbered 1 can be generated in this experiment from 0 to r times. I need to calculate theoretical 95% confidence interval for this count.

asked 2022-06-20

From a collection of objects numbered $\{1,2,....,K\}$ objects are picked and replaced. We want to test ${H}_{0}:K=100000$ against ${H}_{1}<100000$, with the highest ranking number $M$ of our sample as test statistic. We find for our realisation for $M$ the value $81115$.

What is the $P$ value?

The correct answer is: $0.015$

I know that the definition of the $p$-value is:

The p-value is the probability of getting the observed value of the test static or a value with even greater evidence against ${H}_{0}$, if the hypothesis is actually true

or in formula form $P(T\ge t)$

I have the following questions:

What are $T$ and $t$?

I think that distribution is uniform, but how do I calculate the $p$-value?

What is the $P$ value?

The correct answer is: $0.015$

I know that the definition of the $p$-value is:

The p-value is the probability of getting the observed value of the test static or a value with even greater evidence against ${H}_{0}$, if the hypothesis is actually true

or in formula form $P(T\ge t)$

I have the following questions:

What are $T$ and $t$?

I think that distribution is uniform, but how do I calculate the $p$-value?

asked 2022-07-08

Hence, $v(6,000)<v(4,000)+v(2,000)$ and $v(-6,000)>v(-4,000)+v(-2,000)$. These preferences are in accord with the hypothesis that the value function is concave for gains and convex for losses.

What this means and by how we can know if these align with convex and concave functions?

What this means and by how we can know if these align with convex and concave functions?