Answer:
For this case we have the following info related to the time to prepare a return

And we select a sample size =49>30 and we are interested in determine the standard deviation for the sample mean. From the central limit theorem we know that the distribution for the sample mean
is given by:
And the standard deviation would be:

And the best answer would be
b. 2 minutes
Step-by-step explanation:
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 central limit theorem states that "if we have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population with replacement, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large".
Solution to the problem
For this case we have the following info related to the time to prepare a return

And we select a sample size =49>30 and we are interested in determine the standard deviation for the sample mean. From the central limit theorem we know that the distribution for the sample mean
is given by:
And the standard deviation would be:

And the best answer would be
b. 2 minutes
Answer:
140 toy cars
Step-by-step explanation:
The ratio of Ed's toy car to Pete's toy car is initially given as 5:2
Ed gave Pete a total number of 30 cars
Let x represent the greatest common factor that exists between both number
Number of Ed's car is represented as 5x
Number of Pete car is represented as 2x
Since they each have an equal number of cars which is 30 then we can solve for x as follows
5x-30=2x+30
Collect the like terms
5x-2x= 30+30
3x= 60
Divide both sides by the coefficient of x which is 3
3x/3=60/3
x=20
Ed's car is 5x, we substitute 20 for x
5(20)
= 100 cars
Pete car is 2x,we substitute 20 for x
2(20)
= 40 cars
Therefore, the total number of cars can be calculated as follows
= 100+40
= 140 toy cars
Hence they have 140 toy cars altogether
Answer:
We can conclude that on this case we have identical processes but excersise 17 use another way to present the probability distribution and as we can see the expected value can be viewed as a dot product of two vectors with one vector containing the outcomes and the other the probabilities for each possible outcome.
Step-by-step explanation:
Assuming this previous info:
Exercise 17. Suppose that we convert the table on the previous page displaying the discrete distribution for the number of heads occurring when two coins are flipped to two vectors.
Let vector