Questions: If the heights of all adult females are normally distributed with a mean of 5.5 feet and a standard deviation of 1 foot, how tall is Jada if she is in the 82 nd percentile? Round your answer to one decimal place. Do not include units in your answer.
Transcript text: If the heights of all adult females are normally distributed with a mean of 5.5 feet and a standard deviation of 1 foot, how tall is Jada if she is in the 82 nd percentile? Round your answer to one decimal place. Do not include units in your answer.
Solution
Solution Steps
Step 1: Determine the z-score for the 82nd Percentile
To find Jada's height at the 82nd percentile, we first need to identify the z-score corresponding to this percentile. From the z-score table, we find that the closest probability to \(0.82\) is \(0.819\), which corresponds to a z-score of approximately \(Z = 0.92\).
Step 2: Use the z-score to Calculate Jada's Height
We can calculate Jada's height using the formula for converting a z-score to a value in a normal distribution:
\[
X = \mu + Z \cdot \sigma
\]
Where:
\(X\) is the height we want to find,
\(\mu = 5.5\) feet (mean height),
\(Z = 0.92\) (z-score for the 82nd percentile),
\(\sigma = 1\) foot (standard deviation).
Substituting the values into the formula:
\[
X = 5.5 + 0.92 \cdot 1
\]
Calculating this gives:
\[
X = 5.5 + 0.92 = 6.42
\]
Step 3: Round the Result
Finally, we round Jada's height to one decimal place: