Measurements, HW Quizzes 1

The force acting on a beam was measured 9 times under the same operating conditions and the sample standard deviation was 1.44. What is the standard deviation of the means for this data set? (Provide your answer using two decimal places)

0.48

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. This process was repeated by 3 observers. The pooled standard deviations of these 3 data sets was 1.45. Determine the true mean force using all pooled data (with a 95% probability). The result should look like this: True mean = mean +/- Margin of Error (In the answer box, provide this Margin of Error only and use two decimal places) Hint: Use table 4.4 to find the t-value corresponding to the given conditions.

0.82

The force acting on a beam was measured under the same operating conditions and a sample of 7 data points was collected. The mean and standard deviation were; Mean= 50.2, Standard Deviation= 1 Determine the true mean force (with a 95% probability). The result should look like this: True mean = mean +/- Margin of Error (In the answer box, provide this Margin of Error only and use two decimal places) Hint: Use table 4.4 to find the t-value corresponding to the given conditions.

0.92

The force acting on a beam was measured 5 times under the same operating conditions. This process was repeated by 3 observers, resulting in 3 sets of data. The standard deviations of these data sets were: Standard Deviation 1= 1.26, Standard Deviation 2= 0.92, Standard Deviation 3= 0.94 The corresponding mean values were: 52.3, 51.5, and 52.7, respectively. Compute the Pooled Standard Deviation for these data sets. (Provide your answer using two decimal places)

1.05

The force acting on a beam was measured under the same operating conditions and 14 data points were collected. The sample mean was 6.2 and standard deviation was 0.9. We are interested in calculating the margin of error for the true mean. How many degrees of freedom does the data set have? (Provide your answer as integer)

13

You are in charge of monitoring the pressure of a compressed air tank in a processing plant. After repeating the pressure measurement a large number of times, you found that the pressure values have Gaussian distribution with a mean value of 69 psi and a standard deviation of 10 psi. If it is important that the pressure stays below 79 psi, what is the probability (in percent) that the pressure will exceed this value? (Provide your answer as a percentage using two decimal places. Do not include the % symbol in your answer)

15.87

The force acting on a beam was measured under the same operating conditions and a sample of 8 data points was acquired. The mean and standard deviation were: Mean= 50, Standard Deviation= 1 If one additional measurement were made, estimate the interval for this new measurement (at 95% probability). The interval should look like this: interval = mean +/- Value (In the answer box, provide the Value only and use two decimal places) Hint: Use table 4.4 to find the t-value corresponding to the given conditions.

2.37

The force acting on a beam was measured under the same operating conditions and the following data points were collected: 45, 51.6, 46.5, 52.3, 50.8 What is the sample standard deviation of this data set? (Provide your answer using two decimal places)

3.3

The force acting on a beam was measured 5 times under the same operating conditions. This process was repeated by 3 observers, resulting in 3 sets of data. The means of these data sets were: Mean 1= 6, Mean 2= 7, Mean 3= 4 The corresponding standard deviations were: 3.2, 2.1, and 2.5, respectively. Compute the Pooled Mean of the 3 data sets. (Provide your answer using two decimal places)

5.67

The force acting on a beam was measured under the same operating conditions and the following sample of data points were collected: 47.1, 52.9, 49.8, 53.7, 46.5 What is the sample mean of this data set? (Provide your answer using two decimal places)

50

The force acting on a beam was measured under the same operating conditions and a sample of 10 data points was collected. This process was repeated by 8 observers. The corresponding sample mean was 53.4, 54.7, 52.6, respectively. If we are interested in calculating the margin of error for the true mean, determine the number of degrees of freedom for the pooled 8 data sets. (Provide your answer as an integer)

72