Hypothesis z-test

Using traditional methods, it takes 93 hours to receive a basic driving license. A new license training method using Computer Aided Instruction (CAI) has been proposed. A researcher used the technique with 160 students and observed that they had a mean of 92 hours. Assume the variance is known to be 64. A level of significance of 0.02 will be used to determine if the technique performs differently than the traditional method. Find the value of the test statistic. Round your answer to 2 decimal places.

Hypothesis z-test

A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 404.0 gram setting. It is believed that the machine is underfilling the bags. A 47 bag sample had a mean of 403.0 grams. A level of significance of 0.10.1 will be used. Is there sufficient evidence to support the claim that the bags are underfilled? Assume the variance is known to be 729.00.

What is the conclusion?

Hypothesis z-test

An engineer designed a valve that will regulate water pressure on an automobile engine. The engineer designed the valve such that it would produce a mean pressure of 5.3 pounds/square inch. It is believed that the valve performs above the specifications. The valve was tested on 130 engines and the mean pressure was 5.4 pounds/square inch. Assume the standard deviation is known to be 0.7. A level of significance of 0.01 will be used. Make a decision to reject or fail to reject the null hypothesis.

Make a decision.

Hypothesis z-test

An automobile manufacturer claims that its van has a 29.1 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the MPG for this van since it is believed that the van has an incorrect manufacturer's MPG rating. After testing 200 vans, they found a mean MPG of 28.8. Assume the standard deviation is known to be 2.42.4. A level of significance of 0.01 will be used. Find the value of the test statistic. Round your answer to 2 decimal places.

Enter the value of the test statistic.

Hypothesis z-test

A manufacturer of chocolate chips would like to know whether its bag filling machine works correctly at the 404.0 gram setting. It is believed that the machine is underfilling the bags. A 41 bag sample had a mean of 396.0 grams. A level of significance of 0.05 will be used. Determine the decision rule. Assume the standard deviation is known to be 25.0.

Enter the decision rule.

Hypothesis z-test

A manufacturer of chocolate chips would like to know whether its bag filling machine works correctly at the 415.0 gram setting. It is believed that the machine is underfilling the bags. A 35 bag sample had a mean of 413.0 grams. A level of significance of 0.01 will be used. State the hypotheses. Assume the standard deviation is known to be 21.0.

Enter the hypotheses:

Hypothesis t-test

Using traditional methods, it takes 109 hours to receive a basic driving license. A new license training method using Computer Aided Instruction (CAI) has been proposed. A researcher used the technique with 190 students and observed that they had a mean of 110 hours. Assume the standard deviation is known to be 6. A level of significance of 0.05 will be used to determine if the technique performs differently than the traditional method. Is there sufficient evidence to support the claim that the technique performs differently than the traditional method?

What is the conclusion?

Hypothesis t-test

An engineer designed a valve that will regulate water pressure on an automobile engine. The engineer designed the valve such that it would produce a mean pressure of 6.1 pounds/square inch. It is believed that the valve performs above the specifications. The valve was tested on 26 engines and the mean pressure was 6.4 pounds/square inch with a standard deviation of 0.6. A level of significance of 0.05 will be used. Assume the population distribution is approximately normal. Make the decision to reject or fail to reject the null hypothesis.

Hypothesis t-test

Using traditional methods, it takes 11.0 hours to receive a basic driving license. A new license training method using Computer Aided Instruction (CAI) has been proposed. A researcher used the technique with 9 students and observed that they had a mean of 10.8 hours with a standard deviation of 1.5. A level of significance of 0.05 will be used to determine if the technique performs differently than the traditional method. Assume the population distribution is approximately normal. Find the value of the test statistic. Round your answer to three decimal places.

Hypothesis t-test

A lumber company is making boards that are 2764.0 millimeters tall. If the boards are too long they must be trimmed, and if the boards are too short they cannot be used. A sample of 19 is made, and it is found that they have a mean of 2760.2 millimeters with a standard deviation of 12.0. A level of significance of 0.1 will be used to determine if the boards are either too long or too short. Assume the population distribution is approximately normal. Find the value of the test statistic. Round your answer to three decimal places.

Hypothesis t-test

A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 431 gram setting. It is believed that the machine is underfilling the bags. A 18 bag sample had a mean of 421 grams with a standard deviation of 14. A level of significance of 0.01 will be used. Assume the population distribution is approximately normal. State the null and alternative hypotheses.

Hypothesis t-test

A manufacturer of banana chips would like to know whether its bag filling machine works correctly at the 407 gram setting. It is believed that the machine is underfilling the bags. A 28 bag sample had a mean of 402 grams with a standard deviation of 23. A level of significance of 0.025 will be used. Assume the population distribution is approximately normal. Is there sufficient evidence to support the claim that the bags are underfilled?