1 00:00:01,340 --> 00:00:04,830 So we Dandi logistic model with one predictive variable. 2 00:00:05,700 --> 00:00:06,840 And we got this result. 3 00:00:07,950 --> 00:00:10,380 We have the B does it all and B, the one values here. 4 00:00:11,130 --> 00:00:12,630 B, does it with zero point six one. 5 00:00:12,840 --> 00:00:15,420 And B, the one is minus zero point zero three. 6 00:00:17,250 --> 00:00:22,650 Once we get the values or B, does it want to be done, we can calculate the value of probability of 7 00:00:22,650 --> 00:00:24,570 Y is equal to one using the formula. 8 00:00:24,630 --> 00:00:26,820 I showed you in the last lecture. 9 00:00:30,120 --> 00:00:36,210 Now, when we ran the model in the output, we also get these other values, which is standard error, 10 00:00:36,570 --> 00:00:40,800 the value and the probability value, which is also called p value. 11 00:00:42,060 --> 00:00:43,740 I will talk about this briefly here. 12 00:00:47,260 --> 00:00:54,700 All these three values are calculated to establish whether this particular variable, that is the price 13 00:00:54,700 --> 00:00:59,620 variable is actually impacting the very well or not. 14 00:01:02,410 --> 00:01:04,050 Take a moment here and think about it. 15 00:01:05,020 --> 00:01:10,300 This variable will impact the response variable. 16 00:01:11,230 --> 00:01:14,620 Only if the beta corresponding to it is non-zero. 17 00:01:15,910 --> 00:01:20,200 If beta one is zero, whatever change we may make to this variable. 18 00:01:20,620 --> 00:01:22,270 Nothing will happen to the response variable. 19 00:01:24,310 --> 00:01:27,780 So we want to establish that beta one is non-zero. 20 00:01:29,320 --> 00:01:32,980 Mathematically began guided in this hypothesis form. 21 00:01:33,400 --> 00:01:40,300 That null hypothesis is there is no relationship between price and sored variable. 22 00:01:41,670 --> 00:01:44,080 The ordinate is that there is some relationship. 23 00:01:45,340 --> 00:01:46,750 We want to negate that. 24 00:01:46,750 --> 00:01:47,040 We do. 25 00:01:47,080 --> 00:01:54,190 One is zero so that we can establish that price is impacting the response variable. 26 00:01:57,220 --> 00:02:01,780 You may be thinking that we already got a non-zero value for this be done. 27 00:02:03,280 --> 00:02:04,720 So why are we discussing this? 28 00:02:05,320 --> 00:02:14,290 The point is that although we got an expected value of beta using the maximum likelihood method, how 29 00:02:14,290 --> 00:02:17,020 confident are we with this media value? 30 00:02:19,360 --> 00:02:26,200 There is still a chance that it was actually zero, but when we calculated using the maximum likelihood 31 00:02:26,200 --> 00:02:26,560 method. 32 00:02:27,880 --> 00:02:31,510 There is some probability that we are getting this value instead of zero. 33 00:02:33,250 --> 00:02:39,910 So these three values is helping us get that confidence level with which we can say that we do. 34 00:02:39,930 --> 00:02:41,140 One is non-zero. 35 00:02:43,270 --> 00:02:45,250 So the first column is standard error. 36 00:02:46,150 --> 00:02:52,510 Standard error is like standard deviation and represents the expected deviation of the actual return 37 00:02:53,230 --> 00:03:01,180 from these predicted ones to the predicted values zero point zero three and its deviation from the true 38 00:03:01,180 --> 00:03:08,350 value is nearly zero point zero one, corresponding to the standard error because it does devalue. 39 00:03:09,190 --> 00:03:15,130 Zewail You can be noted simply by dividing this estimated beta value by the standard error. 40 00:03:15,430 --> 00:03:22,180 So zero point zero three zero zero zero point zero one is nearly this two point forward value corresponding 41 00:03:22,180 --> 00:03:30,820 to this devalue, which is also called a Zis statistic using a Z statistic graph corresponding to the 42 00:03:30,820 --> 00:03:31,570 Z value. 43 00:03:31,720 --> 00:03:33,640 We can get a P value. 44 00:03:34,420 --> 00:03:40,660 P value is telling us the probability of BITA actually being zero when we are getting the predicted 45 00:03:40,660 --> 00:03:43,240 beta value as minus zero point zero three. 46 00:03:43,720 --> 00:03:51,340 And when the standard edit is zero point zero one, you may be Orvil in these last two lines. 47 00:03:54,990 --> 00:03:55,540 Don't worry. 48 00:03:55,820 --> 00:03:58,200 Here's the key takeaway from these values. 49 00:04:01,640 --> 00:04:06,810 Whenever we get all these values, we just need to check this P-value. 50 00:04:08,690 --> 00:04:12,020 This P-value should be lower than a threshold value. 51 00:04:13,640 --> 00:04:16,280 You can select this threshold as body or convenience. 52 00:04:17,780 --> 00:04:22,730 That threshold will give you the confidence level with which you can say that bidets actually impacting 53 00:04:22,730 --> 00:04:23,300 the response. 54 00:04:23,320 --> 00:04:23,970 Woodinville or not. 55 00:04:25,070 --> 00:04:29,960 Usually we have a threshold value of five percent or one percent. 56 00:04:31,160 --> 00:04:35,420 So as you can see that here, the P value is zero point zero zero six. 57 00:04:36,320 --> 00:04:44,480 This basically means that there is only a zero point zero six percent chance that the actual beta was 58 00:04:44,480 --> 00:04:48,410 zero and we predicted it to be zero point zero three. 59 00:04:50,600 --> 00:04:59,330 Therefore, just look at the P value of all the variables, whichever variable has a P value lower than 60 00:04:59,330 --> 00:05:00,320 a threshold value. 61 00:05:01,070 --> 00:05:05,600 You can state that all those variables are impacting the response variable. 62 00:05:07,280 --> 00:05:09,560 But others, you may not be sure.