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:
Where
and
Since the distribution of X is normal then we know that the distribution for the sample mean
is given by:
And we have;


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
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:
Where
and
Since the distribution of X is normal then we know that the distribution for the sample mean
is given by:
And we have;


Answer:
327 children and 318 adults
Step-by-step explanation:
The x be the amount of children and y be the amount of adults that were at the swimming pool. We can use this to set up a system of equations:
x+y=645
1.75x+2.50y=1367.25
Move y to the other side in the first equation to isolate x and solve the system using substitution:
x=645-y
1.75(645-y)+2.50y=1367.25
Distribute
1128.75-1.75y+2.50y=1367.25
1128.75+0.75y=1367.25
Subtract 1128.75 from both sides
0.75y=238.5
Divide both sides by 0.75
y=318
x=645-y
x=645-318
x=327
327 children and 318 adults swam at the pool that day
If a pencil factory makes 50 cases of pencils in 5 hours. Let's first find out how many cases are made per hour.
50 ÷ 5 = 10 cases per hour
Now you need to know how long it will take to make 55 cases. Since we already know that it takes 5 hours to make 50 cases. So you need to know how many cases for the extra 5 cases. If it takes 1 hour to make 10 cases, it would only take 1/2 hour to make 5 cases.
So it would take 5 1/2 hours to make 55 cases.
Hope this helps. :)
Answer: Hence, there are approximately 48884 integers are divisible by 3 or 5 or 7.
Step-by-step explanation:
Since we have given that
Integers between 10000 and 99999 = 99999-10000+1=90000
n( divisible by 3) = 
n( divisible by 5) = 
n( divisible by 7) = 
n( divisible by 3 and 5) = n(3∩5)=
n( divisible by 5 and 7) = n(5∩7) = 
n( divisible by 3 and 7) = n(3∩7) = 
n( divisible by 3,5 and 7) = n(3∩5∩7) = 
As we know the formula,
n(3∪5∪7)=n(3)+n(5)+n(7)-n(3∩5)-n(5∩7)-n(3∩7)+n(3∩5∩7)

Hence, there are approximately 48884 integers are divisible by 3 or 5 or 7.
The answer is that there is a proximity 10 miles of coast 9.904... it be exact