tests/testthat/_snaps/prop-tests.md

In ISCAM: Companion to the Book "Investigating Statistical Concepts, Applications, and Methods"

iscamonepropztest agrees with prop.test

Code
  res$output
Output
   [1] ""                                                                        
   [2] "One Proportion z test"                                                   
   [3] ""                                                                        
   [4] "Data: observed successes = 35, sample size = 50, sample proportion = 0.7"
   [5] ""                                                                        
   [6] "Null hypothesis       : pi = 0.5 "                                       
   [7] "Alternative hypothesis: pi > 0.5 "                                       
   [8] "z-statistic: 2.828 "                                                     
   [9] "p-value: 0.002339 "                                                      
  [10] "95 % Confidence interval for pi: ( 0.5729798 ,  0.8270202 ) "

iscamonepropztest handles less alternatives with proportion input

Code
  res$output
Output
   [1] ""                                                                         
   [2] "One Proportion z test"                                                    
   [3] ""                                                                         
   [4] "Data: observed successes = 16, sample size = 50, sample proportion = 0.32"
   [5] ""                                                                         
   [6] "Null hypothesis       : pi = 0.35 "                                       
   [7] "Alternative hypothesis: pi < 0.35 "                                       
   [8] "z-statistic: -0.4447 "                                                    
   [9] "p-value: 0.3283 "                                                         
  [10] "90 % Confidence interval for pi: ( 0.2114895 ,  0.4285105 ) "

iscamonepropztest covers two-sided comparisons when sample is below null

Code
  res$output
Output
  [1] ""                                                                        
  [2] "One Proportion z test"                                                   
  [3] ""                                                                        
  [4] "Data: observed successes = 18, sample size = 60, sample proportion = 0.3"
  [5] ""                                                                        
  [6] "Null hypothesis       : pi = 0.4 "                                       
  [7] "Alternative hypothesis: pi <> 0.4 "                                      
  [8] "z-statistic: -1.581 "                                                    
  [9] "p-value: 0.1138 "

iscamonepropztest reports intervals when hypothesis is omitted

Code
  res$output
Output
  [1] ""                                                                          
  [2] "One Proportion z test"                                                     
  [3] ""                                                                          
  [4] "Data: observed successes = 28, sample size = 100, sample proportion = 0.28"
  [5] ""                                                                          
  [6] "90 % Confidence interval for pi: ( 0.2061463 ,  0.3538537 ) "

iscamtwopropztest matches two-sample z test calculations

Code
  res$output
Output
   [1] ""                                                                             
   [2] "Two Proportion z test"                                                        
   [3] ""                                                                             
   [4] "Group1: observed successes = 35, sample size = 50, sample proportion = 0.7"   
   [5] ""                                                                             
   [6] "Group2: observed successes = 28, sample size = 45, sample proportion = 0.6222"
   [7] ""                                                                             
   [8] "Null hypothesis       : pi1-pi2 = 0 "                                         
   [9] "Alternative hypothesis: pi1-pi2 > 0 "                                         
  [10] "z-statistic: 0.8009 "                                                         
  [11] "95 % Confidence interval for pi1-pi2: ( -0.1124861 ,  0.2680417 ) "           
  [12] "p-value: 0.2116 "

iscamtwopropztest handles less alternative with proportion input

Code
  res$output
Output
   [1] ""                                                                             
   [2] "Two Proportion z test"                                                        
   [3] ""                                                                             
   [4] "Group1: observed successes = 25, sample size = 60, sample proportion = 0.4167"
   [5] ""                                                                             
   [6] "Group2: observed successes = 28, sample size = 55, sample proportion = 0.5091"
   [7] ""                                                                             
   [8] "Null hypothesis       : pi1-pi2 = 0 "                                         
   [9] "Alternative hypothesis: pi1-pi2 < 0 "                                         
  [10] "z-statistic: -0.9932 "                                                        
  [11] "90 % Confidence interval for pi1-pi2: ( -0.2449163 ,  0.06006778 ) "          
  [12] "p-value: 0.1603 "

iscamtwopropztest covers two-sided alternatives below the null

Code
  res$output
Output
   [1] ""                                                                             
   [2] "Two Proportion z test"                                                        
   [3] ""                                                                             
   [4] "Group1: observed successes = 20, sample size = 60, sample proportion = 0.3333"
   [5] ""                                                                             
   [6] "Group2: observed successes = 28, sample size = 60, sample proportion = 0.4667"
   [7] ""                                                                             
   [8] "Null hypothesis       : pi1-pi2 = 0 "                                         
   [9] "Alternative hypothesis: pi1-pi2 <> 0 "                                        
  [10] "z-statistic: -1.491 "                                                         
  [11] "p-value: 0.136 "

iscamtwopropztest accepts tabular input and confidence-only intervals

Code
  res_alt$output
Output
   [1] ""                                                                          
   [2] "Two Proportion z test"                                                     
   [3] ""                                                                          
   [4] "Group1: observed successes = 30, sample size = 50, sample proportion = 0.6"
   [5] ""                                                                          
   [6] "Group2: observed successes = 25, sample size = 50, sample proportion = 0.5"
   [7] ""                                                                          
   [8] "Null hypothesis       : pi1-pi2 = 0 "                                      
   [9] "Alternative hypothesis: pi1-pi2 > 0 "                                      
  [10] "z-statistic: 1.005 "                                                       
  [11] "p-value: 0.1574 "

Code
  res_conf$output
Output
  [1] ""                                                                             
  [2] "Two Proportion z test"                                                        
  [3] ""                                                                             
  [4] "Group1: observed successes = 62, sample size = 100, sample proportion = 0.62" 
  [5] ""                                                                             
  [6] "Group2: observed successes = 50, sample size = 90, sample proportion = 0.5556"
  [7] ""                                                                             
  [8] "90 % Confidence interval for pi1-pi2: ( -0.05301566 ,  0.1819045 ) "

iscamonepropztest prints help for question mark

Code
  collapse_output(help_lines)
Output
  [1] "Arguments:\n     observed: The observed number of successes. If a value less than 1 is\n     provided, it is assumed to be the sample proportion.\n     n: The sample size.\n     hypothesized: (optional) hypothesized probability of success under the\n     null hypothesis.\n     alternative: (optional) character string specifying the form of the\n     alternative hypothesis. Must be one of \"less\", \"greater\", or\n     \"two.sided\".\n     conf.level: (optional) confidence level(s) for a two-sided confidence\n     interval.\n     verbose: Logical, defaults to 'TRUE'. Set to 'FALSE' to suppress\n     messages"

iscamtwopropztest prints help for question mark

Code
  collapse_output(help_lines)
Output
  [1] "Arguments:\n     observed1: The observed number of successes in group 1. If a value less\n     than 1 is provided, it is assumed to be the sample\n     proportion.\n     n1: The sample size for group 1.\n     observed2: The observed number of successes in group 2. If a value less\n     than 1 is provided, it is assumed to be the sample\n     proportion.\n     n2: The sample size for group 2.\n     hypothesized: (optional) hypothesized difference in probability of\n     success under the null hypothesis.\n     alternative: (optional) character string specifying the form of the\n     alternative hypothesis. Must be one of \"less\", \"greater\", or\n     \"two.sided\".\n     conf.level: (optional) confidence level(s) for a two-sided confidence\n     interval.\n     datatable: (optional) two-way table of counts as an alternative input\n     method.\n     verbose: Logical, defaults to 'TRUE'. Set to 'FALSE' to suppress\n     messages"

ISCAM documentation built on Feb. 12, 2026, 5:07 p.m.