Question

The following table shows the concentration of a new antibiotic, the total number of infected subjects, and the number of subjects who showed complete recovery:

 

S. No. Concentration ($x_i$) Recovered ($y_i$) Total Subjects ($n_i$)
1 2 10 50
2 4 15 45
3 6 22 40
4 8 35 60
5 10 68 80

 



(i) Fit a logistic regression model considering ẞ=-2.148 and ẞ = 0.36, as the initial values of the parameters. Perform calculations for only one iteration using the Newton-Raphson method.

(ii) Test the significance of the fitted model using the Hosmer-Lemeshow test at 5% level of significance.

 

25 Mar 2026
Answer :
Word Count : 666
Let’s solve this step by step, manually, using the Newton-Raphson method for logistic regression and then apply the Hosmer-Lemeshow test. We are given: * Initial parameter estimates: (\beta_0 = -2.148), (\beta_1 = 0.36) * Observations: (x_i) (concentration), (y_i) (recovered), (n_i) (total subjects) We want one iteration of Newton-Raphson. --- Step 1: Logistic regression basics For a logistic regression: [ \pi_i = \frac{e^{\beta_0 + \beta_1 x_i}}{1 + e^{\beta_0 + \beta_1 x_i}} ] The Newton-Raphson update is: [ \boldsymbol{\beta}^{(new)} = \boldsymbol{\beta}^{(old)} + (\mathbf{X}^\top \mathbf{W} \mathbf{X})^{-1} \mathbf{X}^\top (\mathbf{y} - \boldsymbol{\mu}) ] Where: * (\mathbf{X} = \begin{bmatrix} 1 & x_1 \ \vdots & \vdots \ 1 & x_n \end{bmatrix}) * (\mathbf{W} = \text{diag}(n_i \pi_i (1-\pi_i))) * (\boldsymbol{\mu} = n_i \pi_i) --- Step 2: Compute (\pi_i) with initial estimates [ \pi_i = \frac{e^{\beta_0 + \beta_1 x_i}}{1 + e^{\beta_0 _____ _________ _______ __________ ____ ______ ______ ____ _________.
________ _________ __________ ____ ___ _____ ___ _____ ____.
____ _________ _______ ___ ____ _______ ______ ___ ______ _____ ___ ________.
___ _________ ____ ________ ______ __________ ____ ______ _________ _______ __________ _________.
_____ _________ ___ _______ ______ ____ _______ _____.
___ ______ __________ _____ __________ ______ ___ ____ ___.
_________ ________ _________ ________ __________ ______ ________ _______ ______ _________.
_______ ___ _______ __________ ___ ____ ____ ___.
_______ ________ _________ ____ ________ ______ ______ _______ ________ __________ _____ _____.
___ _____ _______ ______ ____ ____ _________.
____ __________ ___ ___ _________ ______.
_____ ______ _____ ____ ______.
_________ _________ _________ _________ ________ _______ ____ ______ _______ __________ ________ ________.
___ ____ _____ ______ __________ ________ _______ _____ ________.
__________ _______ _________ _____ _________ ___ ______ __________ _______ _______ ____ _____.
_____ __________ _____ _______ ______.
____ ___ _____ ______ ____ ___ ______ ______ _______ ____ _____.
_____ _____ ________ ___ _______ _________.
__________ _________ _________ ____ ___ ______.
__________ __________ _______ _____ ________ __________ ______.
_______ _____ ___ ________ ______ ___ ______ _______ __________ ____.
______ __________ _________ ________ _____ ________.
_____ __________ ____ _________ ___ ________ _____ ________ __________ __________ _____ ________.
_______ _________ ___ _____ _______ ___.
________ ___ ________ ____ _________ _________ ________ _____ _____ _________ _____.
________ _____ __________ __________ ___ ____ _____ ___ ___ ____ ___ _____.
___ ___ ____ _________ _________ ______ ________ _______ ______.
_____ __________ ___ ____ _______.
__________ ________ _______ ____ _____ __________ __________ __________ ____ ______ ____ _______.
________ __________ _______ _____ _______ ____ ___ ______.
_______ _________ ________ ______ __________ ___.
_____ _______ ___ _______ _____ _____ _______ ________ __________.
_______ ______ __________ ______ ____.
_____ ____ _________ ___ __________ ___ __________ ___ ___ _________ ______.
____ __________ _________ _____ _____ _______ ____.
________ ________ _________ _________ ___.
_____ _____ _______ _______ ________ ____ _________ _______.
______ _________ ________ ___ ______ _________ ______ _____ ___ _____ _____.
______ __________ __________ ____ _______ _______ ______ ________ _________ ______ _____ __________.
_________ __________ ____ ______ _______ _____.
____ ____ __________ __________ __________ _________ _________.
_____ __________ _________ ____ ________ _____ ___ _____.
_____ ___ __________ _______ _________ _____ _________ __________ _______.
_______ _______ _____ ______ _______.
___ __________ ___ ________ ________ _________ ______ _____ ___ _______.
______ _________ __________ ______ _______ __________ ______ ___ _________.
______ _______ ______ _______ _______ _____.
________ _________ ____ __________ ________ ______ _________.
_______ _________ ________ _________ ___ _________ _________.
______ ___ ______ ________ _______ ______ _______ _______ ______ _________ ____ _____.
__________ ________ _______ __________ __________ ___ _________ __________ _________.
_________ ___ __________ ____ __________ __________ _____ ________.
_______ ______ _____ _____ _________ _________ _______ ____ ___ _______.
________ _____ ___ __________ ______ _________ ______ _______ _____ ________ _____.
____ ___ ____ ___ ________ ________ _______ _______ __________ ______.
_______ ___ ______ ________ ___ _______ ______ _____ __________ ___ _______.
____ ___ ______ ________ _________ ________ _____ ______.
__________ _______ ____ _________ _______ _________ _________ __________ ______ _________.
___ __________ __________ ________ ___ _________ ______ __________ __________ ________.
______ ___ _____ ______ ___ _______ ____ ___ ______.
____ _________ _______ __________ __________ _________ __________.
______ ______ ___ ______.
Get Full Answer on WhatsApp
IGNOU NEWS
Assignment Submission Last Date Extended Till 30 June 2026 Click Here★★★IGNOU June 2026 TEE Date Sheet Released Click Here★★★
Top
📞
Call Support Instant phone assistance The following table shows the concentration of a new antibiotic, the t
🟢
WhatsApp Chat Fast live messaging
Email Us Business enquiries & support