101k views
1 vote
THE RESULTS OF A SATISTICS EXAMINATION ARE NORMALLY DISTRIBUTED WITH A MEAN OF 74 AND A STANDARD DEVIATION OF 8 FIND THE % OF INDIVIDUALS THAT SCORED LESS THEN A 78

User Baklap
by
7.7k points

1 Answer

4 votes

Given

Mean = 74

standard deviation = 8

Find

percent of individuals that scored less than a 78

Step-by-step explanation

as we have given ,

mean = 74

standard deviation = 8

P(X < 78) =


\begin{gathered} P(Z<(X-\mu)/(\sigma)) \\ =P(Z<(78-74)/(8)) \\ =P(Z<(4)/(8)) \\ =P(Z<0.5) \\ =0.6915\approx69.15\% \end{gathered}

Final Answer

Hence , the percentage of individuals that scored less than 78 is 69.15% or 69.2%

User Andrew Goodnough
by
7.6k points