What is the standard deviation?

I have calculated and calculated and have yet to come up with the correct answer

Mean=70

Data collected:

68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68

IGApply: Week 2 Connect ExerciseinstrQuestion 2 (of 10)>Save & Evalue:10.00 pointsIn a hearing test, subjects estimate the loudness (in decibels) of a sound, and the results are (mean = 70): 68, 67, 70, 71, 68, 75, 68, 62, 80, 73, 68.What is the standard deviation?O 18O4.7322.40O3246.76ReferencesMultiple ChoiceDifficulty: 2 MediumLearning Objective: 03-02 Compute and interpret the range, variance,and standard deviation.2019 McGraw-Hill Education. All rights reserved.2,649MAY17