Statistics homework help

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1. Use these data and simple regression analysis (by Data Analysis tab in Excel) to develop linear regression models for predicting the haul cost by speed for each of these two vehicles. Discuss the strength of the models.
2. Based on the models, predict the haul cost for 35 mph and for 45 mph for each of these vehicles.
· Please submit only one Excel file for this case assignment.

Case Assignment

 

The following is mostly a general description of the Caterpillar company. The questions are related to regression analysis. You will do the same quick analysis in Excel

 

Caterpillar, Inc.

Caterpillar, Inc., headquartered in Peoria, Illinois, is an American corporation with a worldwide dealer network which sells machinery, engines, financial products and insurance. Caterpillar is the world’s leading manufacturer of construction and mining equipment, diesel and natural gas engines, industrial gas turbines and diesel-electric locomotives. Although providing financial services through its Financial Products segment, Caterpillar primarily operates through its three product segments of Construction Industries, Resource Industries, and Energy & Transportation. Some of its manufactured construction products include: mini excavators, small-wheel loaders, backhoe loaders, multi-terrain loaders, and compact-wheel loaders.

Caterpillar tractors have undertaken and completed many difficult tasks since the company’s beginning. In the 1940s, Caterpillar tractors were used in the construction of the Alaskan highway; and between 1944 and 1956, they were used to help construct 70,000 miles of highway in the United States. In the 1950s and 60s, usage of Caterpillar tractors around the world exploded and were used in such countries as Australia, Austria, Ceylon, France, Germany, Italy, Nigeria, Philippines, Rhodesia, Russia, Sweden, Switzerland, Uganda, and Venezuela, in a wide variety of projects. In addition, Caterpillar products were used to help construct the St. Lawrence Seaway between Canada and the United States. In the 1970s and 80s, Caterpillar equipment were used in numerous dam, power, and pipeline projects. Since then, Caterpillars have been used in the construction of several projects such as Japan’s Kansai International Airport as a marine airport approximately three miles offshore in Osaka Bay, the Chunnel between France and England, the “Big Dig” in Boston, Panama Canal expansion, and several Olympic Games sites.

 

Discussion

The United States Department of Agriculture (USDA), in conjunction with the Forest Service, publishes information to assist companies in estimating the cost of building a temporary road for such activities as a timber sale. Such roads are generally built for one or two seasons of use for limited traffic and are designed with the goal of reestablishing vegetative cover on the roadway and adjacent disturbed area within ten years after the termination of the contract, permit, or lease. The timber sale contract requires out sloping, removal of culverts and ditches, and building water bars or cross ditches after the road is no longer needed. As part of this estimation process, the company needs to estimate haul costs. The USDA publishes variable costs in dollars per cubic-yard-mile of hauling dirt according to the speed with which the vehicle can drive. Speeds are mainly determined by the road width, the sight distance, the grade, the curves and the turnouts. Thus, on a flat, straight, wide road, the speed is faster.

 

Shown below are data on speed and cost per cubic yard for two types of vehicles: a 12 cubic yard end-dump vehicle, and a 20 cubic yard bottom-dump vehicle.

 

 

SPEED (MPH)

HAUL COST 12-CUBIC-YARD END-DUMP VEHICLE

($ PER CUBIC YD)

HAUL COST 20-CUBIC-YARD BOTTOM-DUMP VEHICLE

($ PER CUBIC YD)

10

$2.46

$1.98

15

$1.64

$1.31

20

$1.24

$0.98

25

$0.98

$0.77

30

$0.82

$0.65

40

$0.62

$0.47

50

$0.48

$0.40

 

Questions:

 

1. Use these data and simple regression analysis (by Data Analysis tab in Excel) to develop linear regression models for predicting the haul cost by speed for each of these two vehicles. Discuss the strength of the models.

2. Based on the models, predict the haul cost for 35 mph and for 45 mph for each of these vehicles.

 

Please submit only one Excel file for this case assignment.