The mean plus the standard deviation is:

1 answer:

3 0

Answer: variable is distributed normally, then approximately two-thirds of the population will within plus or minus one standard deviation of the mean

Step-by-step explanation:

The standard deviation is calculated as the square root of variance by determining each data point's deviation relative to the mean. If the data points are further from the mean, there is a higher deviation within the data set; thus, the more spread out the data, the higher the standard deviation.

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Nora uses 2 feet of ribbon to make a bow. She has 8 yards of ribbon. how many bows can she makes?

zimovet [89]

She can make 12 bows because there are 3 feet in one yard so 8*3 is 24. then you divide 24 by 2 and you get 12
2ft ribbon=1bow
8 yards of ribbon
1yard=3ft
She can make 12 bows!~
I hope this helps!~

7 0

3 years ago

In September 2011, Gallup surveyed 1,004 American adults and asked them whether they blamed Barack Obama a great deal, a moderat

Alexus [3.1K]

Answer:

The 99% confidence interval for the proportion of all American adults who blame Barack Obama a great deal or a moderate amount for U.S. economic problems is (0.4894, 0.5706)..

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

For this problem, we have that:

$n = 1004, \pi = 0.53$

99% confidence level

So $\alpha = 0.01$ , z is the value of Z that has a pvalue of $1 - \frac{0.01}{2} = 0.995$ , so $Z = 2.575$ .

The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.53 - 2.575\sqrt{\frac{0.53*0.47}{1004}} = 0.4894$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.53 - 2.575\sqrt{\frac{0.53*0.47}{1004}} = 0.5706$

The 99% confidence interval for the proportion of all American adults who blame Barack Obama a great deal or a moderate amount for U.S. economic problems is (0.4894, 0.5706)..

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2 years ago

Rebecca was advised to invest her £12000 life savings in a special High

Evgesh-ka [11]

#1st year

$\\ \rm\Rrightarrow 12000+0.045(12000)=12540$