Table:
characteristics
geometric mean
95% confidence interval

from
to

total
1.3
1.1
1.4

age group

6 to 8
1.8
1.6
2.1

9 to 11
1.4
1.2
1.7

12 to 14
1.2
1.0
1.4

15 to 17
0.9
0.8
1.1

sex

male
1.2
1.1
1.4

female
1.3
1.2
1.5

time of urine collection

morning
1.1
1.0
1.3

afternoon
1.5
1.3
1.7

evening
1.4
1.0
1.7

ethnicity

white
1.3
1.2
1.5

non-white
1.3
1.0
1.6

exposure to second-hand smoke

once a week or less
1.2
1.1
1.4

every day or almost every day
1.6
1.4
2.0

household income

low/lower-middle
1.7
1.4
2.0

upper-middle
1.2
1.0
1.4

highest
1.2
1.1
1.4

household education

secondary school graduation or less
1.3
1.0
1.6

at least some postsecondary
1.3
1.1
1.5

body mass index

neither overweight nor obese
1.3
1.2
1.5

overweight
1.3
1.0
1.7

obese
1.2
1.0
1.4

Statement: children and youth in low and lower-middle income households had significantly higher bpa concentrations than did those in the highest income households.
Question: list the household income with the highest bpa concentrations.
Answer: low/lower-middle