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Talja [164]
3 years ago
14

a previous analysis of paper boxes showed that the standard deviation of the length is 9mm. What is the 98% confidence interval

for the average length of a box. How many boxes does he need to measure to be accurate within 3 millimeters.
Mathematics
1 answer:
il63 [147K]3 years ago
6 0
We cannot calculate the confidence interval without the sample size.  However, for the second question, the sample size needed would be 49.

The formula we use is

n=(\frac{z_{\frac{\alpha}{2}}\times \sigma}{E})^2

To find the z-score:
Convert 98% to a decimal:  0.98
Subtract from 1:  1-0.98 = 0.02
Divide by 2:  0.02/2 = 0.01
Subtract from 1:  1-0.01 = 0.99

Using a z-table (http://www.z-table.com) we see that this value is closest to a z-score of 2.33.

Using the z-score, our standard deviation (9) and our margin of error (3), we have:
n=(\frac{2.33(9)}{3})^2=(6.99)^2=48.86\approx 49
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The figure shows a construction completed by hand.
Tresset [83]

Based on the construction, we can logically deduce that: A. yes; the compass was kept at the same width to create the arcs for points C and D.

<h3>What is a line segment?</h3>

A line segment can be defined as the part of a line in a geometric figure such as a triangle, circle, quadrilateral, etc., that is bounded by two (2) distinct points and it typically has a fixed length.

In Geometry, a line segment can be measured by using the following measuring instruments:

  • A scale (ruler)
  • A divider
  • A compass

<h3>What is an arc?</h3>

In Geometry, an arc can be defined as a trajectory that is generally formed when the distance from a given point has a fixed numerical value.

Based on the construction with arcs created above and below the line segment from points A, we can infer and logically deduce that it is true that the compass was kept at the same width to create the arcs for points C and D.

In conclusion, yes, the construction demonstrated how to bisect a line segment correctly by hand.

Read more on arcs here: brainly.com/question/11126174

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Complete Question:

The construction has a given segment AB. Arcs have been created above and below the segment from points A that are equidistant from point A. The compass was kept at the same distance, placed on point B, and two additional arcs were created above and below the segment that intersect with the first arcs created. The intersection of the arcs above the segment created point C. The intersection of the arcs below the segment created point D. A line was drawn from point C to D through the segment.

Does the construction demonstrate how to bisect a segment correctly by hand?

A. Yes; the compass was kept at the same width to create the arcs for points C and D.

B. Yes; a straightedge was used to create segment CD.

C. No; the compass was not kept at the same width to create the arcs for points C and D.

D. No; a straightedge was used to create segment CD.

7 0
2 years ago
The number of girls who work at Super shopper is 2 more than 3 times the number of boys. If 30 boys work at super shopper; how m
mote1985 [20]
I think its 92 but im not entirely sure. hope it helps though
4 0
3 years ago
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Each wheel on Nina's car has has a diameter of 18 inches.Which expression could be used to find the circumference of the wheel?
serg [7]

Answer:

56.548667764616276

Step-by-step explanation:

Multiply the diameter by pi.

C= 18 x 3.14159265

Hope this helps!

7 0
3 years ago
How old do you got to be to drop out
bazaltina [42]

Answer:

Step-by-step explanation:

high school with pariantal consent

6 0
3 years ago
Santos is a lifeguard and spots a drowning child 50 meters along the shore and 60 meters from the shore to the child. Santos run
Amanda [17]

Answer:

Santos should run approximately 36.145 meters along the shore

Step-by-step explanation:

The given parameters are;

The distance along the shore of the child = 50 meters

The distance from the shore of the child = 60 meters

The rate at which Santos can run = 4 m/s

The rate he can swim = 0.9 m/s

Let 'x' represent the distance he runs along the shore

We have;

The time he spends running on the shore, t₁ = x/4

The time he spends swimming, t₂ = (√(60² + (50 - x)²)/0.9

The total time, T = t₁ + t₂ = x/4 + (√(60² + (50 - x)²)/0.9

To find the maximum, we have;

dT/dx = 0 = d(x/4 + (√(60² + (50 - x)²)/0.9)/dx = 1/4 - (50 - x)/(0.9·(√(60² + (50 - x)²) = 0

1/4 - (50 - x)/(0.9·(√(60² + (50 - x)²) = 0

Simplifying using a graphing calculator gives;

\dfrac{x - 2000}{9} = \sqrt{x^2-100\cdot x+6,100}

1519·x² - 151900·x + 3505900 = 0

x = (151900 ± √((-151900)² - 4×1519×3505900))/(2 × 1519)

x ≈ 63.86 m or x ≈ 36.145 m

We note that the distance from a point x = 63.83 meters and 36.145 meters from where Santos spots the girl to the location of the girl are the same

Therefore, Santos should run approximately 36.145 meters along the shore before jumping into to the water in order to save the child

7 0
3 years ago
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