per square foot vs. median household income Looking for correlations

Looking for correlations per square foot vs. median household income

DemoMC
SalePrice GLA CostperSf Population MedianIncome HousingUnits

1 21480000 89909 239. 1286000 55636. 499956
2 28500000 75000 380 278238 69974. 105743
3 19800000 79828 248. 304288 68058. 118825
4 8300000 79000 105. 3416617 74329. 1090028
5 20750000 83379 249. 5828786 52377. 1875525
6 16500000 103000 160. 4726091 63046. 1411244
7 37550000 101195 371. 1483212 77417. 599161
8 29500000 83281 354. 3993337 54947. 1416236
9 18250000 120437 152. 2006603 83087. 681384

quick tip; google can be very useful.
If I google '"correlation in r"' ; I get half a million results; while I doubt the accuracy of that... the top 10 seem pretty relevant/good sources to learn from.

Take the overall view first

d <- data.frame(
            id = c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L),
     SalePrice = c(21480000L,28500000L,19800000L,
                   8300000L,20750000L,16500000L,37550000L,29500000L,18250000L),
           GLA = c(89909L,75000L,79828L,79000L,83379L,
                   103000L,101195L,83281L,120437L),
     CostperSf = c(239, 380, 248, 105, 249, 160, 371, 354, 152),
    Population = c(1286000L,278238L,304288L,3416617L,
                   5828786L,4726091L,1483212L,3993337L,2006603L),
  MedianIncome = c(55636,69974,68058,74329,52377,
                   63046,77417,54947,83087),
  HousingUnits = c(499956L,105743L,118825L,1090028L,
                   1875525L,1411244L,599161L,1416236L,681384L)
)
pairs(d)

Created on 2023-01-25 with reprex v2.0.2