During the manufacture of certain electrical components, items go through a series of heat processes. The length of time spent in this heat treatment is related to the useful life of the component. To find the nature of this relationship a sample of 20 components was selected from the process and tested to destruction. The results are presented below:
a. Draw the scatter diagram for this data.
b. Find the regression line of useful life on time spent in process.
c. Predict the useful life of a component which spends 33 minutes in process.
d. Predict the useful life of a component which spends 60 minutes in process.
e. Using a suitable transformation, find a regression relationship which has a higher coefficient of determination.
f. From this new relationship, predict the useful life of a component which spends 33 minutes in process.
g. From this new relationship, predict the useful life of a component which spends 60 minutes in process.
Question -2
Four regions of Yorkshire classify companies according to primary, manufacturing, transport, retail and service. The number of companies working in each region within each category is shown below. Construct a suitable diagram to represent this data and comment on the regional differences.
=================================================== Question-1 During the manufacture of certain electrical components, items go through a series of heat processes. The length of time spent in this heat treatment is related to the useful life of the component. To find the nature of this relationship a sample of 20 components was selected from the process and tested to destruction. The results are presented below: a. Draw the scatter diagram for this data. b. Find the regression line of useful life on time spent in process. c. Predict the useful life of a component which spends 33 minutes in process. d. Predict the useful life of a component which spends 60 minutes in process. e. Using a suitable transformation, find a regression relationship which has a higher coefficient of determination. f. From this new relationship, predict the useful life of a component which spends 33 minutes in process. g. From this new relationship, predict the useful life of a component which spends 60 minutes in process. Question -2 Four regions of Yorkshire classify companies according to primary, manufacturing, transport, retail and service. The number of companies working in each region within each category is shown below. Construct a suitable diagram to represent this data and comment on the regional differences. Question -3 Given the following distribution of weekly household income: a. calculate the mean and standard deviation; b. estimate the percentage of households with a weekly income below the mean; c. determine the median and quartile deviation. Question -4 The following two grouped frequency distributions represents the times, over a one week period, that patients had to wait before seeing a doctor in the Accident and Emergency department of two hospitals. a. determine the mean and standard deviation of waiting times for each hospital; b. determine the coefficient of variation and a measure of skew for each hospital’s waiting times; d. with reference parts (a), (b) discuss the differences in waiting times between the two hospitals.