HELP PLS ASAP 50 POINTS HELP ILL MARK BRAINLIEST

The fracture strength of tempered glass averages 14 (measured in thousands of pounds per square inch) and has standard deviation

Wewaii [24]

Answer:

0.1587 = 15.87% probability that the average fracture strength of 100 randomly selected pieces of this glass exceeds 14.2.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

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.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

The fracture strength of tempered glass averages 14 (measured in thousands of pounds per square inch) and has standard deviation 2.

This means that $\mu = 14, \sigma = 2$

Sample of 100:

This means that $n = 100, s = \frac{2}{\sqrt{100}} = 0.2$

What is the probability that the average fracture strength of 100 randomly selected pieces of this glass exceeds 14.2?

This is 1 subtracted by the p-value of Z when X = 14.2. So

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

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{14.2 - 14}{0.2}$

$Z = 1$

$Z = 1$ has a p-value of 0.8413.

1 - 0.8413 = 0.1587

0.1587 = 15.87% probability that the average fracture strength of 100 randomly selected pieces of this glass exceeds 14.2.

6 0

3 years ago

If a rope 36 feet long is cut into two pieces in such a way that one piece is twice as long as the other piece, how long must th

SVEN [57.7K]

24 feet long :)
All I did was I divided the 36 into 3 equal parts of 12, then doubled the 12 to make that longer piece 24 feet. This 24 foot piece would be twice as long as the other leftover 12 foot piece since 12x2=24

4 0

3 years ago

GARDENING Jane needs to buy mulch

PSYCHO15rus [73]

Answer:

I suggest you use Socratic, it solves questions like this.

Step-by-step explanation:

7 0

3 years ago

Handles-n-Things is a small enterprise company buying new carpet for their office room. The room is 15 ft. wide and 24 ft. long.

Helen [10]

Hey there!

To find the area, we multiply the length by the width! The carpet will cover the area of the room.

24×15=360

But, the carpeting is sold in square yards, not feet. There are three feet in a yard, which means that one yard is 1/3 feet. Since we have 360 square feet, we will divide it by three to get yards.

360/3=120

Therefore, the office would need 120 square yards of carpeting.

Have a wonderful day!

4 0

3 years ago

A classroom has a length of 30 ft. and a width of 20 ft. The flooring is to be replaced by tiles. If each tile has a length of 3

Mashcka [7]

Answer:

100

Step-by-step explanation:

Hello! to calculate the number of tiles needed for the floor you need two things

1. number of tiles that fit across the width, this is achieved by dividing the total width by the width of each tile

Width=20ft=240in

$N1=\frac{240}{24} =10$

2.number of tiles that fit in the logitude, this is achieved by dividing the total length by the length of each tile.

leght=30ft=360in

$N2=\frac{360}{36} =10$

Finally, you multiply the number of tiles that fit in width by the number of tiles that fit in length.

N=10X10=100

3 0

3 years ago