Answer:
29.2
Explanation:
Mean = 21.4
Standard deviation = 5.9%
The minimum score required for the scholarship which is the scores of the top 9% is calculated using the Z - Score Formula.
The Z- score formula is given as:
z = x - μ /σ
Z score ( z) is determined by checking the z score percentile of the normal distribution
In the question we are told that it is the students who scores are in the top 9%
The top 9% is determined by finding the z score of the 91st percentile on the normal distribution
z score of the 91st percentile = 1.341
Using the formula
z = x - μ /σ
Where
z = z score of the 91st percentile = 1.341
μ = mean = 21.4
σ = Standard deviation = 5.9
1.341= x - 21.4 / 5.9
Cross multiply
1.341 × 5.9 = x - 21.4
7.7526 = x -21.4
x = 7.7526 + 21.4
x = 29.1526
The 91st percentile is at the score of 29.1526.
We were asked in the question to round up to the nearest tenth.
Approximately, = 29.2
Explanation: