Question 1 table 1 shows the number of customers visited by...

Question 1: Table 1 shows the number of customers visited by a salesman over an 80-week period. Table 1: Customers Visited Over an 80-Week Period 68 64 75 82 68 60 62 88 76 93 73 79 88 73 60 93 71 59 85 75 61 65 75 87 74 62 95 78 63 72 66 78 82 75 94 77 69 74 68 60 96 78 89 61 75 95 60 79 83 71 79 62 67 97 78 85 76 65 71 75 65 80 73 57 88 78 62 76 53 74 86 67 73 81 72 63 76 75 85 77 d) Calculate the variance and standard deviation

Transcript

00:01 Hey there, welcome to numerate.

00:04 So we have a problem here where a salesman is tracking the number of customers that visited in an 80 -week time period, right? so we've given 80 values here, but to calculate the variance in standard deviation.

00:18 Okay, so are we using sample variance or population variance in standard deviation? so since n is greater than 30, in this case, n equals, 80 and it does not specify to use sample then we we can assume we can assume that it is population okay the reason why we need to know is population or sample is because when we're calculating the standard deviation and variance we're going to do n minus 1 if it's sample but if population then we just divide by n we don't minus 1 okay so let's start up by finding our variance so our variance would be since this is a population we're going to denote it as sigma six square so it will be the square root the square root of the sum of squares x minus x mean squared and this is going to be divided by n divided by n right that so with this equation we can find a variance but we would need the mean in order to so so um our mean uh you should denote it as mu actually because this population so let me fix this should be mu for population mill equals sum of all the values divided by the number of values, which is, in this case, is 80.

02:57 Okay, so we're going to calculate our mean.

03:01 I mean will equals around 74 .6.

03:07 And now we can plug this into here, right? and then we can calculate our variance.

03:16 Sigma squared equals.

03:23 Just calculate our sigma square, which is variance...

Question

Please give Ace some feedback