﻿It 
  was 
  necessary 
  to 
  separate 
  the 
  resident 
  from 
  the 
  nonresident 
  skiers 
  to 
  avoid 
  

   counting 
  them 
  more 
  than 
  once 
  because 
  many 
  skiers 
  had 
  skied 
  in 
  several 
  of 
  the 
  Western 
  

   States 
  . 
  

  

  Total 
  numbers 
  of 
  visits 
  per 
  State 
  were 
  available 
  only 
  for 
  the 
  1963-64 
  season. 
  

   On 
  the 
  other 
  hand, 
  the 
  skiers 
  questioned 
  described 
  their 
  activities 
  during 
  the 
  1964-65 
  

   season. 
  Therefore, 
  the 
  proportion 
  of 
  resident 
  and 
  nonresident 
  visits 
  and 
  average 
  days 
  

   skied 
  per 
  skier 
  relating 
  to 
  the 
  1964-65 
  season 
  were 
  used 
  to 
  convert 
  the 
  1963-64 
  attend- 
  

   ance 
  data. 
  This 
  created 
  an 
  opportunity 
  for 
  error 
  in 
  estimating 
  the 
  size 
  of 
  the 
  skier 
  

   population 
  for 
  a 
  State 
  if 
  either 
  the 
  proportion 
  of 
  resident 
  to 
  nonresident 
  skier 
  visits 
  or 
  

   the 
  average 
  number 
  of 
  days 
  skied 
  per 
  skier 
  changed 
  substantially 
  between 
  the 
  two 
  sea- 
  

   sons. 
  Although 
  it 
  seems 
  unlikely, 
  because 
  both 
  seasons 
  had 
  adequate 
  snowfall, 
  the 
  size 
  

   of 
  the 
  resident 
  skier 
  population 
  could 
  be 
  either 
  larger 
  or 
  smaller 
  than 
  that 
  estimated. 
  

  

  All 
  references 
  to 
  numbers 
  of 
  skiers 
  apply 
  to 
  the 
  1963-64 
  season. 
  Proportions 
  of 
  

   the 
  skier 
  population's 
  particular 
  characteristics 
  (age, 
  sex, 
  etc.) 
  relate 
  to 
  the 
  1964-65 
  

   skier 
  population. 
  

  

  RELIABILITY 
  OF 
  SKIER 
  DATA 
  

  

  Because 
  all 
  skier 
  data 
  are 
  based 
  on 
  samples 
  rather 
  than 
  on 
  an 
  inventory, 
  the 
  

   estimates 
  are 
  subject 
  to 
  some 
  error 
  dependent 
  on 
  the 
  size 
  and 
  completeness 
  of 
  the 
  

   sample. 
  Reliable 
  measures 
  of 
  the 
  sample 
  estimates 
  for 
  (1) 
  the 
  average 
  number 
  of 
  

   days 
  skied 
  during 
  the 
  season 
  per 
  skier, 
  (2) 
  the 
  average 
  expenditure 
  per 
  skier, 
  and 
  

   (3) 
  the 
  percent 
  of 
  the 
  skier 
  population 
  having 
  specific 
  attributes 
  such 
  as 
  age, 
  sex, 
  

   income, 
  and 
  others 
  are 
  presented 
  in 
  the 
  following 
  tables: 
  

  

  Table 
  2 
  shows 
  the 
  estimated 
  average 
  (mean) 
  number 
  of 
  days 
  skied 
  per 
  resident 
  

   and 
  nonresident 
  skier 
  during 
  the 
  1964-65 
  season 
  within 
  each 
  State 
  and 
  gives 
  the 
  standard 
  

   error 
  of 
  each 
  average 
  (mean) 
  as 
  a 
  plus 
  or 
  minus 
  (±) 
  figure. 
  In 
  Alaska, 
  for 
  example, 
  

   we 
  would 
  expect 
  to 
  find 
  the 
  average 
  (or 
  mean) 
  between 
  16.478 
  and 
  16.522 
  days 
  per 
  sea- 
  

   son 
  per 
  skier. 
  The 
  true 
  average 
  of 
  the 
  entire 
  population 
  can 
  generally 
  be 
  expected 
  to 
  

   be 
  not 
  more 
  than 
  ±0. 
  1 
  of 
  a 
  day 
  larger 
  or 
  smaller 
  than 
  that 
  estimated 
  from 
  the 
  sample. 
  

  

  Table 
  3 
  shows 
  the 
  estimated 
  average 
  (mean) 
  daily 
  expenditure 
  per 
  skier 
  during 
  

   the 
  1964-65 
  season 
  and 
  shows 
  the 
  standard 
  error 
  of 
  each 
  average 
  (mean) 
  as 
  a 
  plus 
  or 
  

   minus 
  dollar 
  amount. 
  In 
  Alaska, 
  for 
  example, 
  we 
  should 
  expect 
  the 
  true 
  average 
  daily 
  

   expenditure 
  per 
  resident 
  skier 
  to 
  be 
  somewhere 
  between 
  $11.54 
  and 
  $18.92. 
  

  

  Table 
  4 
  shows 
  the 
  confidence 
  limits 
  (at 
  the 
  95 
  -percent 
  level 
  ) 
  for 
  five 
  different 
  

   percentage 
  groups 
  for 
  the 
  skier 
  population 
  that 
  may 
  be 
  estimated 
  to 
  have 
  a 
  certain 
  

   characteristic 
  - 
  -such 
  as 
  the 
  percent 
  of 
  skiers 
  that 
  are 
  males, 
  females--or 
  that 
  fall 
  in 
  

   a 
  particular 
  income 
  class, 
  age 
  group, 
  etc. 
  In 
  Alaska, 
  for 
  example, 
  the 
  confidence 
  

  

  The 
  95 
  -percent 
  confidence 
  level 
  indicates 
  that 
  the 
  true 
  proportion 
  would 
  fall 
  

   within 
  the 
  plus 
  or 
  minus 
  range 
  indicated 
  95 
  out 
  of 
  100 
  times 
  sampled. 
  

  

  56 
  

  

  