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zepelin [54]
3 years ago
15

Suppose the bank installs nine alarms. What is the expected number of alarms that will detect a burglar?

Mathematics
1 answer:
Harrizon [31]3 years ago
3 0
The answer is 6 because
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The delivery times for all food orders at a fast-food restaurant during the lunch hour are normally distributed with a mean of m
UkoKoshka [18]

Answer:

Let X the random variable that represent the delivery times of a population, and for this case we know the distribution for X is given by:

X \sim N(14.7,3.7)  

Where \mu=14.7 and \sigma=3.7

Since the distribution of X is normal then we know that the distribution for the sample mean \bar X is given by:

\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})

And we have;

\mu_{\bar X}= 14.70

\sigma_{\bar X} =\frac{3.7}{\sqrt{40}}= 0.59

Step-by-step explanation:

Assuming this question: The delivery times for all food orders at a fast-food restaurant during the lunch hour are normally distributed with a mean of 14.7 minutes and a standard deviation of 3.7 minutes. Let R be the mean delivery time for a random sample of 40 orders at this restaurant. Calculate the mean and standard deviation of \bar X Round your answers to two decimal places.

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

Solution to the problem

Let X the random variable that represent the delivery times of a population, and for this case we know the distribution for X is given by:

X \sim N(14.7,3.7)  

Where \mu=14.7 and \sigma=3.7

Since the distribution of X is normal then we know that the distribution for the sample mean \bar X is given by:

\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})

And we have;

\mu_{\bar X}= 14.70

\sigma_{\bar X} =\frac{3.7}{\sqrt{40}}= 0.59

4 0
3 years ago
If it takes 5 workers 4 hours to build a 10 foot wall, and the number of hours is directly proportional to the number of walls t
pychu [463]
4x10=40 10x10=100 ft/10 100/10=10 walls
4 0
3 years ago
<img src="https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7Bx-5%7D" id="TexFormula1" title="\sqrt[3]{x-5}" alt="\sqrt[3]{x-5}" align="abs
sashaice [31]

Answer:

It cannot be solved furthur bro as the value of x is unspecified

6 0
3 years ago
Hey please help this is due today ​
Aleksandr [31]

Answer:

100

Step-by-step explanation:

Write in an equation:

4=4%x, then divide 4% from both sides, and then you get 100.

7 0
2 years ago
Read 2 more answers
Which statement correctly identifies a local minimum of the graphed function? Over the interval [–3, –2], the local minimum is 0
marta [7]

Answer:

C.

Step-by-step explanation:

As we can see on the graph C is our answer.

4 0
3 years ago
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