According to Sturge's rule, number of classes or bins recommended to construct a frequency distribution is k ≈ 7
Sturge's Rule: There are no hard and fast guidelines for the size of a class interval or bin when building a frequency distribution table. However, Sturge's rule offers advice on how many intervals one can make if one is genuinely unable to choose a class width. Sturge's rule advises that the class interval number be for a set of n observations.
Given,
n = 66
We know that,
According to Sturge's rule, the optimal number of class intervals can be determined by using the equation:

Here, n is equal to 66 and by substituting the value to the equation we get:

k = 7.0444
k ≈ 7
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The equation of best fit is y = (-22/5)x + 10.
What is an equation of a line?
The equation of a line is given by:
y = mx + c where m is the slope of the line and c is the y-intercept.
Example:
The slope of the line y = 2x + 3 is 2.
The slope of a line that passes through (1, 2) and (2, 3) is 1.
We have,
The following coordinates are given:
Pick two coordinates.
(0, 10) and (25, -100)
The equation of best fit.
y = mx + c
Now,
m = (-100 - 10) / (25 - 0)
m = -110 / 25
m = -22/5
Now,
(0, 10) = (x, y)
10 = (-22/5) x 0 + c
c = 10
Now,
y = mx + c
y = (-22/5)x + 10
Thus,
Using the coordinates the equation of best fit is y = (-22/5)x + 10.
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Answer:
Step-by-step explanation:
let side of cube=x cm
volume=x³ cm³
again side=(x-3) cm
volume=(x-3)³ cm³
x³-(x-3)³=1385
(a³-b³)=(a-b)(a²+ab+b²)
(x-x+3){x²+x(x-3)+(x-3)²}=1385
3(x^2+x²-3x+x²-6x+9)=1385
3(3x²-9x+9)=1385
9x²-27x+27=1385
9x²-27x+27-1385=0
9x²-27x-1358=0

We let y equal to the elevation above sea level so that the elevation of the rock climber after x minutes of climbing would be:
y = 2x + 50
His initial height can be calculated when x is equal to zero it is when the climber is not yet climbing. Therefore, the rock climber'sinitial height above sea level would be 50 meters.
Answer:
Step-by-step explanation:
So this is an isosceles triangle so the other angle must be x too.
So:
x+x+40 = 180
2x+40 = 180
2x = 140
x = 70