Question 1

If an experiment produces a result having a p value less than 0.05,what is the probability that any differences found would have been observed even if the null hypothesis is true?

Accepted Answer

A p-value less than 0.05 indicates there is less than a 1 in 20 chance that the observed differences would occur if the null hypothesis were true.

Question 2

The coefficient of determination is

Accepted Answer

The coefficient of determination is also known as R-squared, which is the ratio of the explained variation (which is the variation in the dependent variable that is explained by the independent variable) to the total variation (which is the variation in the dependent variable regardless of whether it is explained or not by the independent variable). Therefore, it is the ratio of the explained variation to the total variation, which is choice B.

Question 3

A colleague generates a best-fit line through a set of data points and asks you to confirm its usefulness and goodness-of-fit.You perform a root-mean-squared-error (RMSE)calculation and come up with a very small RMSE value.Based on this value you determine that the best-fit line

Accepted Answer

A small RMSE value indicates a small difference between the predicted values from the best-fit line and the actual values of the data points. This indicates a good fit between the best-fit line and the data points. Therefore, choice B is correct. Choices A, C, and D are incorrect based on the explanation given.

Question 4

Using linear regression,you compare two different methods for quantifying LDL in a serum sample.Which of the following is NOT acceptable practice when using regression lines?

Accepted Answer

Extrapolation of points outside the standard curve is not an acceptable practice when using regression lines. This is because the regression line is only valid within the range of the data used to create it. Extrapolation, or extending the regression line beyond the range of the data, can lead to inaccurate predictions and should be avoided. The other options, calculation of the slope, identification of the y-intercept, and interpolation within the range of the data, are all acceptable practices when using linear regression.

Question 5

Why is it necessary for a clinical laboratory professional to develop a strong understanding of statistics?

Accepted Answer

All of the options are valid reasons why a clinical laboratory professional should develop a strong understanding of statistics. Comprehending research data is important for interpreting results and making informed decisions, while understanding statistical methods is essential for verifying equipment accuracy and evaluating manufacturer instructions for laboratory testing. Overall, a strong grasp of statistics is critical for ensuring the accuracy and validity of laboratory results.

Question 6

Which of the following sets of data would be bimodal?

Accepted Answer

The answer of Which of the following sets of data...

Question 7

A laboratory technician measures the concentration of serum glucose in a sample ten times and obtains the following results: 32,84,84,86,87,87,87,88,89,89
Which of the following is most impacted by the presence of the outlier value?

Accepted Answer

The mean is most impacted by the presence of the outlier value (32) because it is calculated by adding all values and dividing by the number of values, making it sensitive to extreme values. The median and mode are less affected by outliers; the median is the middle value when data are ordered, and the mode is the most frequently occurring value(s).

Question 8

What does the mode of a data set represent?

Accepted Answer

The mode of a data set represents the value that occurs most frequently. It is not the same as the mean or median.

Question 9

The correlation coefficient of two variables is r = 0.5.What is the coefficient of determination for these variables?

Accepted Answer

The coefficient of determination is the square of the correlation coefficient. Therefore, (0.5)^2 = 0.25. Choice D is the correct answer.

Question 10

The central tendency of a numerical data set refers to

Accepted Answer

The central tendency of a numerical data set refers to the value that typifies the data, such as the mean, median, or mode. Accuracy and precision relate to the reliability of the measurement equipment, and plotting data on a logarithmic scale can reveal patterns in the data but does not relate to central tendency.

Question 11

How does one calculate the mean of a data set?

Accepted Answer

To calculate the mean of a data set, you need to add all the values together and divide the sum by the number of values. This gives you the average value of the data set. Option B only takes into account the largest and smallest value, which may not be representative of the whole data set. Option C assumes that there are only two values, which may not be the case. Option D only takes into account the two middle values, which may not be appropriate for data sets with odd numbers of values.

Question 12

Which of the following statements regarding significance tests is true?

Accepted Answer

Nonrejection of the null hypothesis simply means that there is not enough evidence to reject it based on the current data. It does not mean that the null hypothesis is true with absolute certainty.

Question 13

The standard deviation of a data set can be calculated from the following equation. s =
$\sqrt{\frac{\sum_{i=1}^{n}\left(x_{i}-x\right)^{2}}{n-1}}$
What does the value under the sigma (i = 1)represent?

Accepted Answer

The value under the sigma (i = 1) represents the starting point of the summation, indicating the value of the first data point in the series.

Question 14

When linear regression fails to fit a straight line to the data,what method can be applied to determine the relationship between two variables?

Accepted Answer

When linear regression fails to fit a straight line to the data, the best method to determine the relationship between two variables is nonlinear regression. Nonlinear regression is a method of finding the best fit curve for a set of data points by allowing the functional form of the relationship between the variables to be more complex than a simple straight line. Other options like coefficient determination, expansion of the sum, and specimen pairing may not be effective in determining the relationship between two variables when linear regression fails.

Question 15

What is a major disadvantage of just reporting the mean,median,and mode of a data set?

Accepted Answer

Reporting just the mean, median, and mode of a data set does not provide any information about the variability or spread of the data. Thus, it is important to use additional measures like standard deviation or interquartile range to understand the dispersion of data.

Question 16

A manufacturer-supplied sample of serum glucose is known to contain 85 mg/dL.A co-worker runs a test of the sample on a new piece of laboratory equipment and determines it to be 84 mg/dL.What can be inferred about the new laboratory equipment?

Accepted Answer

The equipment is accurate because the measured value (84 mg/dL) is very close to the known value (85 mg/dL). Precision cannot be determined from a single measurement.

Question 17

You are provided the following set of data: 20,21,28,42,43,43,50 Which value represents the median of this data set?

Accepted Answer

The median is the middle value when a data set is ordered from least to greatest. In this set, the middle value is 42, making it the median.

Quiz 8: Statistics

If an experiment produces a result having a p value less than 0.05,what is the probability that any differences found would have been observed even if the null hypothesis is true?

The coefficient of determination is

A colleague generates a best-fit line through a set of data points and asks you to confirm its usefulness and goodness-of-fit.You perform a root-mean-squared-error (RMSE) calculation and come up with a very small RMSE value.Based on this value you determine that the best-fit line

Using linear regression,you compare two different methods for quantifying LDL in a serum sample.Which of the following is NOT acceptable practice when using regression lines?

Why is it necessary for a clinical laboratory professional to develop a strong understanding of statistics?

Which of the following sets of data would be bimodal?

A laboratory technician measures the concentration of serum glucose in a sample ten times and obtains the following results: 32,84,84,86,87,87,87,88,89,89 Which of the following is most impacted by the presence of the outlier value?

What does the mode of a data set represent?

The correlation coefficient of two variables is r = 0.5.What is the coefficient of determination for these variables?

The central tendency of a numerical data set refers to

How does one calculate the mean of a data set?

Which of the following statements regarding significance tests is true?

The standard deviation of a data set can be calculated from the following equation. s = $\sqrt{\frac{\sum_{i=1}^{n}\left(x_{i}-x\right) ^{2}}{n-1}}$ What does the value under the sigma (i = 1) represent?

When linear regression fails to fit a straight line to the data,what method can be applied to determine the relationship between two variables?

What is a major disadvantage of just reporting the mean,median,and mode of a data set?

A manufacturer-supplied sample of serum glucose is known to contain 85 mg/dL.A co-worker runs a test of the sample on a new piece of laboratory equipment and determines it to be 84 mg/dL.What can be inferred about the new laboratory equipment?

You are provided the following set of data: 20,21,28,42,43,43,50 Which value represents the median of this data set?

Quiz 8: Statistics

If an experiment produces a result having a p value less than 0.05,what is the probability that any differences found would have been observed even if the null hypothesis is true?

The coefficient of determination is

A colleague generates a best-fit line through a set of data points and asks you to confirm its usefulness and goodness-of-fit.You perform a root-mean-squared-error (RMSE) calculation and come up with a very small RMSE value.Based on this value you determine that the best-fit line

Using linear regression,you compare two different methods for quantifying LDL in a serum sample.Which of the following is NOT acceptable practice when using regression lines?

Why is it necessary for a clinical laboratory professional to develop a strong understanding of statistics?

Which of the following sets of data would be bimodal?

A laboratory technician measures the concentration of serum glucose in a sample ten times and obtains the following results: 32,84,84,86,87,87,87,88,89,89 Which of the following is most impacted by the presence of the outlier value?

What does the mode of a data set represent?

The correlation coefficient of two variables is r = 0.5.What is the coefficient of determination for these variables?

The central tendency of a numerical data set refers to

How does one calculate the mean of a data set?

Which of the following statements regarding significance tests is true?

The standard deviation of a data set can be calculated from the following equation. s = ∑i=1n(xi−x) 2n−1\sqrt{\frac{\sum_{i=1}^{n}\left(x_{i}-x\right) ^{2}}{n-1}}n−1∑i=1n​(xi​−x) 2​​ What does the value under the sigma (i = 1) represent?

When linear regression fails to fit a straight line to the data,what method can be applied to determine the relationship between two variables?

What is a major disadvantage of just reporting the mean,median,and mode of a data set?

A manufacturer-supplied sample of serum glucose is known to contain 85 mg/dL.A co-worker runs a test of the sample on a new piece of laboratory equipment and determines it to be 84 mg/dL.What can be inferred about the new laboratory equipment?

You are provided the following set of data: 20,21,28,42,43,43,50 Which value represents the median of this data set?

The standard deviation of a data set can be calculated from the following equation. s = $\sqrt{\frac{\sum_{i=1}^{n}\left(x_{i}-x\right) ^{2}}{n-1}}$ What does the value under the sigma (i = 1) represent?