# The grade point averages (GPA) for 12 randomly selected college students are shown on the right. Complete parts (a) through (c) 2.23.52.7Ebelow.1.80.54.02.21.33.9Assume the population is normally distributed.0.42.23.1(a) Find the sample mean.x = 2.32 (Round to two decimal places as needed.)(b) Find the sample standard deviations 1.29 (Round to two decimal places as needed.)

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I'm having a hard time solving part (b) correctly. I'm using the formula

s = sqrt [ Σ ( xi – x_bar )2 / ( n – 1 ) ].  For Σ ( xi – x_bar )2 I get the value 18.3132 and for ( n – 1 ) the value 11. When I solve for s= 1.29. However, it is the incorrect answer. I'm not sure what I'm doing wrong. I receive the value 18.3132 from subtracating the sample mean from each data entry and squared the result. The sum of all the results to equals 18.3132.

Can you please explain what I should do differently to get the correct answer. Thanks help_outlineImage TranscriptioncloseThe grade point averages (GPA) for 12 randomly selected college students are shown on the right. Complete parts (a) through (c) 2.2 3.5 2.7E below. 1.8 0.5 4.0 2.2 1.3 3.9 Assume the population is normally distributed. 0.4 2.2 3.1 (a) Find the sample mean. x = 2.32 (Round to two decimal places as needed.) (b) Find the sample standard deviation s 1.29 (Round to two decimal places as needed.) fullscreen
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Step 1

According to the provided information,

Step 2

In order to calculate the standard deviation ... help_outlineImage Transcriptionclose|(X -X_bar)^2 х 2.2 0.013611111 0.266944444 1.8 2.2 0.013611111 0.4 3.673611111 3.5 1.400277778 0.5 3.300277778 1.3 1.033611111 2.2 0.013611111 2.7 0.146944444 4 2.833611111 3.9 2.506944444 3.1 0.613611111 Total 15.81666667 2.316666667 mean 1.199115836 fullscreen

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