Find a 90% confidence interval for the difference in mean breaking strength between the two types of yarn.

A sample of 125 pieces of yarn had mean breaking strength 6.1 N and standard deviation 0.7 N. A new batch of yarn was made, using new raw materials from a different vendor. In a sample of 75 pieces of yarn from the new batch, the mean breaking strength was 5.8 N and the standard deviation was 1.0 N.


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Answer the following statement(s) true (T) or false (F)

1. DC motors can be operated at a slow speed with a high torque. 2. If it is necessary to operate the motor above base speed, the field voltage is increased and armature voltage is fully applied. 3. Generally, DC motors are run at base speed or below. 4. A signal electronics module provides the overall drive control. 5. When power is applied to the drive, each of the circuit boards is simultaneously checked by the microprocessor.

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Which of the following statements is LEAST-Likely true?

A. As the engine operates, rings will rotate from the position where they were first installed. B. End gap position is one of the causes of oil consumption. C. If an engine has operated for 100,000 miles or more without an unusual wear problem, the rod can safely be reused with new bearing inserts. D. A bent rod will show wear on opposite sides of the rod bearings.

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Find the displacement in cubic inches of an 8-cylinder engine with a bore of 3.434 inches and a stroke of 3.345 inches. Round to the nearest tenth.

A. 243.8 B. 245.4 C. 246.5 D. 247.8

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A helper is always needed for _____.

Fill in the blank(s) with the appropriate word(s).

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