To find the percentage of data below a Z-score of +0.78, we use the standard normal distribution table or a calculator.

1. Find the cumulative probability for the Z-score of +0.78. This gives us the proportion of the data below this Z-score.

Using the Z-table or a standard normal distribution calculator:

• The cumulative probability for a Z-score of +0.78 is approximately 0.7823.

2. Convert to a percentage: $0.7823 \times 100 = 78.23\%$

So, approximately 78.23% of the data falls below a Z-score of +0.78.

Would you like further details or have any other questions?

Related Questions:

1. What is the percentage of data above a Z-score of +0.78?
2. How do you calculate the Z-score for a given value in a data set?
3. What is the probability for a Z-score of -0.78?
4. How can you use Z-scores to compare two different data sets?
5. How is the standard normal distribution used in hypothesis testing?

Tip:

When using a Z-table, remember that it provides the cumulative probability from the mean up to the Z-score value for positive Z-scores and from the Z-score down for negative values.