The life expectancy (in hours) of a fluorescent tube is normally distributed with a mean 8000 and a standard deviation 1000. Find the probability that a tube lasts for more than 11000 hours.

The life expectancy of a fluorescent tube is normally distributed with a mean of 6, 800 hours and a standard deviation of 1,000 hours. Find the probability that a tube lasts for more than 8,800 hours.

Calculate Z as follows:

z=(x-μ)/σ
=(11000-8000)/1000
=3

From probability tables, find
P(Z>z).
P(Z>3)=1-P(Z<3)=1-0.99865=0.00135

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As a Senior High school student how much time do you spent in studying and answering the activities in your modules?Do you spend 25 hours in a week or more than that?Suppose that the average number of hours spent by Senior High school students in your school for their modular classes in a week is 25 hours with a standard deviation of 4 hours.Assuming that the study is true and the data is normally distributed,what is the probability that a random sample of 12 senior high school students spends more than 24 hours?

Well, the probability of a fluorescent tube lasting more than 11000 hours can be calculated by finding the area under the curve to the right of 11000 hours. Let me do some calculations...

[Clown Bot puts on a clown wig and starts juggling some numbers]

Assuming a standard normal distribution with a mean of 8000 and a standard deviation of 1000, we can standardize the value of 11000 to determine the corresponding z-score.

The z-score is calculated as follows:

z = (x - μ) / σ

Where:
x = 11000
μ = 8000
σ = 1000

Substituting the values, we get:

z = (11000 - 8000) / 1000
= 3000 / 1000
= 3

Now, we need to find the probability of a z-score greater than 3. Using a standard normal distribution table or calculator, we find that the probability of a z-score greater than 3 is approximately 0.0013.

So, the probability that a fluorescent tube lasts for more than 11000 hours is approximately 0.0013, or about 0.13%.

[Clown Bot removes the wig and stops juggling]

Remember, statistics may not be the most exciting topic, but with a little twist of humor, it becomes slightly less dull, just like fluorescent lighting!

To find the probability that a tube lasts for more than 11000 hours, we need to calculate the area under the normal distribution curve to the right of this value.

We can standardize the value of 11000 using the formula for z-score:
z = (x - μ) / σ

Where:
x = value (11000 hours)
μ = mean (8000 hours)
σ = standard deviation (1000 hours)

Substituting the values, we get:
z = (11000 - 8000) / 1000
z = 3

Now, we need to calculate the probability of a z-score greater than 3. We can do this using a standard normal distribution table or a statistical software.

Using a standard normal distribution table, we can find the area corresponding to a z-score of 3. The area to the left of z = 3 is 0.9987. Therefore, the area to the right of z = 3 is 1 - 0.9987 = 0.0013.

So, the probability that a tube lasts for more than 11000 hours is approximately 0.0013, or 0.13%.