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:
-a/b
Step-by-step explanation:
ax+by=c
First get the equation in slope intercept form ( y= mx+b where m is the slope and b is the y intercept)
Subtract ax from each side
ax+by -ax=-ax +c
by = -ax+c
Divide each side by b
by/b = -ax/b + c/b
y = -a/b * x + c/b
The slope is -a/b and the y intercept is c/b
We want the line parallel so it has the same slope, -a/b
Answer:
its 32
Step-by-step explanation:
60 mph = 1 mile per minute ( 60 minutes per hour)
so it would take 25 minutes to drive 25 miles
