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lora16 [44]
3 years ago
14

A sample of 20 joint specimens of a particular type gave a sample mean proportional limit stress of 8.41 mpa and a sample standa

rd deviation of 0.77 mpa.
Mathematics
1 answer:
nignag [31]3 years ago
3 0

For this problem, the confidence interval is the one we are looking for. Since the confidence level is not given, we assume that it is 95%.

 

The formula for the confidence interval is: mean ± t (α/2)(n-1) * s √1 + 1/n


Where:

<span>
</span>

α= 5%


α/2 = 2.5%


t 0.025, 19 = 2.093 (check t table)


n = 20


df = n – 1 = 20 – 1 = 19

So plugging in our values:


8.41 ± 2.093 * 0.77 √ 1 + 1/20


= 8.41 ± 2.093 * 0.77 (1.0247)


= 8.41 ± 2.093 * 0.789019


= 8.41 ± 1.65141676


<span>= 6.7586 < x < 10.0614</span>

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Ymorist [56]

By solving the quadratic equation using completing the square method we got that Penelope should have added 4 to both sides instead of adding 1.

<h3>What is quadratic equation ?</h3>

Any equation of the form ax^2+bx+c=0 where x is variable and a, b, and c are any real numbers where a ≠ 0 is called quadratic equation .

Given work of Penelope is

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Now we can see that Penelope determined the solutions of the quadratic function by completing the square. so he must have been done as following

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By solving the quadratic equation using completing the square method we got that Penelope should have added 4 to both sides instead of adding 1.

To learn more about quadratic equations visit : brainly.com/question/1214333

8 0
2 years ago
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Answer:

Raspuns corect: b)

Step-by-step explanation:

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(9, 8) is the midpoint of mc136-1.jpg. The coordinates of S are (10, 10). What are the coordinates of R?
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so endpoint R has coordinates of (8,6) <===
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