The first step on this question is to convert the 19% over into a Z score using either a calculator or normal distribution table. Since you’re looking for the right-tail probability on this one the Z score here would be 0.88 after rounding to 2 decimal places.
From there then you can apply the Z score formula!
Z = (x – mean) / (standard deviation / sqrt(sample size))
0.88 = (x – 761) / (9/sqrt(10))
2.505 = x – 761
x = 763.50
Rounding up to the nearest gram that would be 764 grams.
I hope that helps! :)
