Answer:
12.3
Step-by-step explanation:
Step 1
We find the mean
The data list shows the scores of ten students in Mr. Smith's math class. 61, 67, 81, 83, 87, 88, 89, 90, 98, 100
Mean = Sum of terms/Number of terms
Number of terms = 10
Mean = 61 + 67 + 81 + 83 + 87 + 88 + 89 + 90 + 98 + 100/10
Mean = 844/10
Mean = 84.4
Step 2
Standard deviation
The formula for sample standard deviation =
√(x - Mean)²/n - 1
= √[(61 - 84.4)² + (67 - 84.4)² + (81 - 84.4)² + (83 - 84.4)² + (87 - 84.4)² + (88 - 84.4)² + (89 - 84.4)² + (90 - 84.4)² + (98 - 84.4)² + (100 - 84.4)²]/10 - 1
=√ 547.56 + 302.76 + 11.56 + 1.96 + 6.76 + 12.96 + 21.16 + 31.36 + 184.96 + 243.36/10 - 1
= √1364.4/9
= √151.6
= 12.31259518
Approximately to the nearest tenth = 12.3
The standard deviation = 12.3
Answer:
4m^2-3mn^2+5
Step-by-step explanation:
Answer in the attachments.
Answer:
84.85cm
Step-by-step explanation:
Let the sides of the square be x
The perimeter of the square = 4x
Get x using the pythagoras theorem
x^2 + x^2 = 30^2
2x^2 = 900
x^2 = 450
x = 21.21cm
Perimeter of the plate = 4(21.21)
Perimeter of the plate = 84.85cm
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