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katrin [286]
3 years ago
15

Which answer is the approximate standard deviation of the data set?

Mathematics
1 answer:
Anna35 [415]3 years ago
6 0

Answer:

3.4

Step-by-step explanation:

Standard deviation of a population is defined as:

σ² = ∑(xᵢ − μ)² / n

The standard deviation of a sample is defined as:

s² = ∑(xᵢ − x)² / (n - 1)

It's not clear which one we have, so let's calculate both.

First, we must find the mean.

μ = (5+12+15+10+12+6+8+8) / 8

μ = 9.5

Now we find the squares of the differences:

(5-9.5)² + (12-9.5)² + (15-9.5)² + (10-9.5)² + (12-9.5)² + (6-9.5)² + (8-9.5)² + (8-9.5)²

= 80

Divide by n:

σ² = 80 / 8

σ² = 10

And take the square root:

σ = √10

σ ≈ 3.2

That's not one of the answers, so let's try the standard deviation of a sample instead of a population.

Instead of dividing by n, we'll divide by n-1:

s² = 80 / 7

And take the square root:

s = √(80/7)

s ≈ 3.4

So that must be it.

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8(7+6+11) help please
scZoUnD [109]

Answer:

The correct answer is 192

3 0
2 years ago
Find the upper 20%of the weight?
meriva

Answer:

The upper 20% of the weighs are weights of at least X, which is X = 0.84\sigma + \mu, in which \sigma is the standard deviation of all weights and \mu is the mean.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the z-score of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Upper 20% of weights:

The upper 20% of the weighs are weighs of at least X, which is found when Z has a p-value of 0.8. So X when Z = 0.84. Then

Z = \frac{X - \mu}{\sigma}

0.84 = \frac{X - \mu}{\sigma}

X = 0.84\sigma + \mu

The upper 20% of the weighs are weights of at least X, which is X = 0.84\sigma + \mu, in which \sigma is the standard deviation of all weights and \mu is the mean.

6 0
2 years ago
Four
damaskus [11]
The probability is 50% for heads, so you should expect 2 heads results

4 0
3 years ago
The hourly wages earned by 20 employees are shown in the first box-and-whisker plot below. The person earning $15 per hour quits
agasfer [191]

Answer:

<h2>The mean decreases, and the median remains the same.</h2>

Step-by-step explanation:

Remember that a box plot is made by the quartiles of the distribution, the maximum value and the minimum value. So, from a box plot we can deduct the range, the median and the interquartile range.

In this case, the median remains the same at $9.5 per hour. The median is indicated by the middle line of the box, and you can observe that it doesn't change.

Now, the range of the data set decreases from 7 to 3.

On the other hand, the mean must decrease, because data greater than $11 doesn't exist in the box plot number 2, and the mean is a central measure sensible to those changes.

Therefore, the right answer is <em>The mean decreases, and the median remains the same.</em>

8 0
3 years ago
Whats my grade if I got 126 answers right of 200?
Romashka-Z-Leto [24]

Answer: 63%

Step-by-step explanation:

Divide 126/200

7 0
3 years ago
Read 2 more answers
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