If M = 45 and SD = 5, what percentage of scores falls between 39 and 51.2?
I need to work the problem in excel.
To find the percentage of scores that fall between 39 and 51.2, you can use the Z-score formula and Excel's built-in functions.
The Z-score formula is:
Z = (X - M) / SD
Where:
Z is the Z-score,
X is the observed value,
M is the mean, and
SD is the standard deviation.
In this case, you want to calculate the Z-score for both 39 and 51.2. The formula becomes:
Z39 = (39 - M) / SD
Z51.2 = (51.2 - M) / SD
To calculate this in Excel, you can use the following steps:
1. Enter the values for M and SD in separate cells. Let's assume M is in cell A1 and SD is in cell B1.
2. Enter the observed values 39 and 51.2 in separate cells, let's assume 39 is in cell A2 and 51.2 is in cell A3.
3. In an empty cell, use the formula: =(A2 - $A$1) / $B$1, which calculates the Z-score for 39. The dollar signs before the cell references will keep them fixed when copying the formula.
4. Copy the formula to another cell, which will calculate the Z-score for 51.2. The cell references should adjust accordingly.
5. Finally, subtract the two Z-scores to find the percentage of scores between 39 and 51.2. If the Z-scores are in cells C2 and C3, use the formula: =ABS(C3 - C2) * 100
The resulting value will be the percentage of scores between 39 and 51.2.