A dihybrid cross was carried out between two plants to determine whether the genes for seed shape and colour are linked. If the genes are unlinked, the expected ratio of 9:3:3:1 should occur. A chi-squared test was carried out on the observed results of the cross. The critical value for chi squared at the 5 % level of significance in this test was 7.82. The calculated value for chi squared was 6.25. What can be concluded from this data?