Question

In: Statistics and Probability

Solve the question below: The following table illustrates a sample of maintenance task times observations. Use...

Solve the question below:

The following table illustrates a sample of maintenance task times observations. Use the information in the table to calculate your responses for each of the questions.

74.66 75.40 47.18 59.63 59.87
57.36 55.94 66.00 43.45 51.22
62.26 69.15 66.61 53.03 59.51
53.97 46.62 63.77 70.50 68.93
56.73 40.51 57.30 55.07 54.89
35.85 69.60 52.93 61.05 64.62
43.85 53.27 50.87 59.96 42.15
51.67 61.65 42.87 57.15 52.57
60.49 53.82 43.75 64.07 67.35
54.10 68.07 55.83 34.05 57.83

Calculate the mean Mct and standard deviation for this sample.

Compute the percentage of corrective time between 40 and 50 minutes by using the standard normal table.

Solutions

Expert Solution

x=a sample of maintenance task times observations

> x=scan("clipboard");x
Read 50 items
[1] 74.66 57.36 62.26 53.97 56.73 35.85 43.85 51.67 60.49 54.10 75.40 55.94
[13] 69.15 46.62 40.51 69.60 53.27 61.65 53.82 68.07 47.18 66.00 66.61 63.77
[25] 57.30 52.93 50.87 42.87 43.75 55.83 59.63 43.45 53.03 70.50 55.07 61.05
[37] 59.96 57.15 64.07 34.05 59.87 51.22 59.51 68.93 54.89 64.62 42.15 52.57
[49] 67.35 57.83
> m=mean(x);m
[1] 56.5796
> s=sqrt(var(x));s
[1] 9.630489

# mean Mct and standard deviation for this sample is 56.5796 and 9.630489

# the percentage of corrective time between 40 and 50 minutes by using the standard normal is
> #p(40<x<50)=P(X<50)-P(x<40)
> pnorm(50,m,s)-pnorm(40,m,s)
[1] 0.2046652

ie 20.47 %

#also manually

p(40<x<50)

=P(-1.7216<z<-0.6832)

=P(Z<-0.6832)-P(Z<-1.7216)

#value of z is obtain from standatrd normal table

=0.2472-0.0426

=0.2047

#the percentage of corrective time between 40 and 50 minutes  is 20.47 %


Related Solutions

The table below lists maintenance cost vs. the age of cars for a sample of seven...
The table below lists maintenance cost vs. the age of cars for a sample of seven cars. The goal was determine if there was a correlation between the age of a car and the cost to maintain it. The least squares regression equation describing the maintenance costs (Y′) vs. the age of the car (X) was determined to be Y' = −4.75 + 2.8929X Age of Car (yrs) Maintenance Costs ($hundreds) 2 3 3 5 4 6 5 7 6...
Suppose there is a random sample of 1,083 observations, divided into four groups. The table below...
Suppose there is a random sample of 1,083 observations, divided into four groups. The table below summarizes the observations that were seen in each group. Group 1 Group 2 Group 3 Group 4 531 184 101 267 We are interested in testing the Null hypothesis Observed=Expected, under the assumption that the expected proportions are .50, .20, .10, and .20 for the 4 groups, respectively. What are the expected values? Group 1 Group 2 Group 3 Group 4 Number Number Number...
Suppose there is a random sample of 400 observations, divided into four groups. The table below...
Suppose there is a random sample of 400 observations, divided into four groups. The table below summarizes the count of observations that were seen in each group. Group 1 Group 2 Group 3 Group 4 240 40 40 80 We are interested in testing the null hypothesis H0:p1=p2=p3=p4=0.25, against the alternative hypothesis HA:Atleastoneproportionisincorrect. a) What is the expected count for each of the groups? Expected:   b) What is the value of the test statistic? Round your response to at least...
Suppose there is a random sample of 200 observations, divided into three groups. The table below...
Suppose there is a random sample of 200 observations, divided into three groups. The table below summarizes the count of observations that were seen in each group. Group 1 Group 2 Group 3 102 40 58 We are interested in testing the null hypothesis H0:p1=0.5,p2=0.2,p3=0.3, against the alternative hypothesis HA:Atleastoneproportionisincorrect. a) What is the value of the test statistic? Round your response to at least 2 decimal places.      b) What conclusion can be made at the 5% level of...
4. The following are 20 observations of response times (in seconds) from a random sample of...
4. The following are 20 observations of response times (in seconds) from a random sample of participants on a cognitive psychology task: 1.7       0.8       4.3       2.9       2.3       1.1       2.2       1.8       2.0       1.2       4.4       1.6       3.8       1.5       2.8 3.3       1.8       2.5       2.7       1.6 (a) Calculate the mean and unbiased standard deviation of the response times. (b) Construct and interpret a 95% confidence interval for μ, which is the true mean response time. Assume that σ = 1.5. (c) Construct and interpret...
Use the table below to solve this problem. Level of Output and Income (GDP = DI)...
Use the table below to solve this problem. Level of Output and Income (GDP = DI) Consumption Saving APC APS MPC MPS $480 $488 $-8 1.0167 –0.0167 0.8 0.2 520 520 0 1.0000 0.0000 0.8 0.2 560 552 8 0.9857 0.0143 0.8 0.2 600 584 16 0.9733 0.0267 0.8 0.2 640 616 24 0.9625 0.0375 0.8 0.2 680 648 32 0.9529 0.0471 0.8 0.2 720 680 40 0.9444 0.0556 0.8 0.2 760 712 48 0.9368 0.0632 0.8 0.2 800 744...
Use the data given below to answer the following question(s). The following table exhibits the age...
Use the data given below to answer the following question(s). The following table exhibits the age of second-hand furniture and the corresponding prices. Use the table to answer the following question(s). (Hint: Use scatter diagram and XLMiner where necessary.) Number of Years Values 2 1856 14 348 7 1020 5 1530 10 349 8 780 9 653 3 1830 10 750 6 1300 Q1. What is the relationship between the age of the furniture and their values? _ _________________ Q2....
Use the following table to answer the question below. If you have the standard utility function...
Use the following table to answer the question below. If you have the standard utility function described in the lecture with A = 6, and you think the future will be like the 1926-1946 period, what fraction of your investments should be in the T-bill (i.e., the portfolio weight of T-bill)? Round your answer to 4 decimal places. For example, if your answer is 3.205%, then please write down 0.0321. time S&P500 ret. T-bill ret. Std. dev. 1926-2012 11.67% 3.58%...
Use the table for the question(s) below . Consider the following expected returns, volatilities, and correlations:...
Use the table for the question(s) below . Consider the following expected returns, volatilities, and correlations: Stock Expected Return Standard Deviation Correlation with Duke Energy Correlation with Microsoft Correlation with Wal Mart − Duke Energy 14% 6% 1.0 1.0 − 0.0 Microsoft 44% 24% 1.0 − 1.0 0.7 Wal Mart − 23% 14% 0.0 0.7 1.0 Which of the following combinations of two stocks would give you the biggest reduction in risk? A. Microsoft and Duke Energy B. Duke Energy...
Case study#2: The Great Depression The Figure below illustrates the Great Depression. At times, such as...
Case study#2: The Great Depression The Figure below illustrates the Great Depression. At times, such as when many people are in need of government assistance, it is easy to tell how the economy is doing. This photograph shows people lined up during the Great Depression, waiting for relief checks. At other times, when some are doing well and others are not, it is more difficult to ascertain how the economy of a country is doing. Question: Interpret the role of...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT