The A1C test is a blood test used to measure the average level of glucose in the blood over the last two to three months, and is used as a means of checking how well blood sugar levels are being controlled for a person with diabetes.ore detail and supporting information is in the body of this article. 1  A1C is an abbreviation for glycated hemoglobin, which forms when glucose attaches to a protein in red blood cells. 2  As blood glucose levels rise, so does the percentage of glycated hemoglobin, so A1C is used to measure diabetes control.
Note: To see if multiple ratios are proportional, you could write them as fractions, reduce them, and compare them. If the reduced fractions are all the same, then you have proportional ratios.
A standard normal distribution table shows a cumulative probability associated with a particular z-score. Table rows show the whole number and tenths place of the z-score. Table columns show the hundredths place. The cumulative probability (often from minus infinity to the z-score) appears in the cell of the table.o find the cumulative probability of a z-score equal to -1.31, cross-reference the row of the table containing -1.3 with the column containing 0.01. The table shows that the probability that a standard normal random variable will be less than -1.31 is 0.0951; that is, P(Z.