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
Learn more about Sturge's rule here: brainly.com/question/28184369
#SPJ4
Answer:
A,
Step-by-step explanation:
Answer:
Step-by-step explanation:
If each day equal chance then p = Prob that a person is borne on a particular day = 1/365
Each person is independent of the other and there are two outcomes either borne in July or not
p = prob for one person not borne in July = (365-31)/365 = 334/365
a)Hence prob that no one from n people borne in July = 
b) p = prob of any one borne in July or Aug =
=0.1698
X- no of people borne in July or Aug
n =15
P(X>=2) =
=0.7505
Answer:
Any number smaller than 2
Step-by-step explanation:
You would graph this by wrighting a solid, filled in circle with an arrow point toward the negative numbers, because those numbers are smaller than 2
Since if he gets the driveway done in 20 minutes he gets 1/20th of the driveway done in 1 minute (if x=20 then x/20=1 by dividing both sides by 20) and if his brother gets 1/12th of the driveway done in one minute, then if t represents the time it takes to shovel the driveway, t/20+t/12=1 driveway shoveled as 1/20+1/12=amount they can do in 1 minute, so t/20+t/12 is how much they can do in t minutes. Multiplying both sides by 20*12=240, we get 12t+20t=32t=240. Dividing both sides by 32, we get 240/32=7.5 minutes to shovel the driveway.