Mendocino: math · Schoolio

The shaded band is this county's normal range. If nothing about how it works changes, nearly every future year should land inside it. Zero means the typical student just meets the state standard. The small numbers under the years are how many students were tested.

Step 1 · Each year's result

For each grade tested, take the average (mean) scale score from the California Department of Education's results file, and subtract the lowest score that counts as "Standard Met" for that grade. That is the grade's distance from standard. Weight each grade by its share of the students tested, then add the grades up. Grades where the state hides the average because ten or fewer students tested are left out entirely.

2015 from sb_ca2015_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	43,051	2384.7	− 2436	−51.3	× 939 / 6426	−7.5
4	43,054	2426.9	− 2485	−58.1	× 1022 / 6426	−9.2
5	43,055	2450.7	− 2528	−77.3	× 902 / 6426	−10.9
6	43,058	2474.8	− 2552	−77.2	× 909 / 6426	−10.9
7	43,059	2494.3	− 2567	−72.7	× 903 / 6426	−10.2
8	43,062	2503.4	− 2586	−82.6	× 910 / 6426	−11.7
11	43,063	2537.8	− 2628	−90.2	× 841 / 6426	−11.8
Sum, rounded to a whole point						−72

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	39,741	2399.5	− 2436	−36.5	× 936 / 6479	−5.3
4	39,743	2439.9	− 2485	−45.1	× 949 / 6479	−6.6
5	39,745	2459.3	− 2528	−68.7	× 1031 / 6479	−10.9
6	39,747	2469.4	− 2552	−82.6	× 904 / 6479	−11.5
7	39,749	2494.1	− 2567	−72.9	× 915 / 6479	−10.3
8	39,751	2506.8	− 2586	−79.2	× 924 / 6479	−11.3
11	39,754	2533.9	− 2628	−94.1	× 820 / 6479	−11.9
Sum, rounded to a whole point						−68

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	40,765	2397.3	− 2436	−38.7	× 917 / 6511	−5.5
4	40,766	2440.6	− 2485	−44.4	× 944 / 6511	−6.4
5	40,769	2459.8	− 2528	−68.2	× 935 / 6511	−9.8
6	40,770	2466.7	− 2552	−85.3	× 1014 / 6511	−13.3
7	40,772	2495.4	− 2567	−71.6	× 903 / 6511	−9.9
8	40,775	2503.7	− 2586	−82.3	× 926 / 6511	−11.7
11	40,776	2537.6	− 2628	−90.4	× 872 / 6511	−12.1
Sum, rounded to a whole point						−69

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	40,786	2404.3	− 2436	−31.7	× 920 / 6523	−4.5
4	40,787	2437.0	− 2485	−48	× 909 / 6523	−6.7
5	40,790	2466.2	− 2528	−61.8	× 954 / 6523	−9
6	40,791	2466.0	− 2552	−86	× 960 / 6523	−12.7
7	40,794	2492.7	− 2567	−74.3	× 1037 / 6523	−11.8
8	40,795	2502.7	− 2586	−83.3	× 894 / 6523	−11.4
11	40,798	2525.8	− 2628	−102.2	× 849 / 6523	−13.3
Sum, rounded to a whole point						−69

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	40,937	2408.2	− 2436	−27.8	× 974 / 6666	−4.1
4	40,938	2444.9	− 2485	−40.1	× 936 / 6666	−5.6
5	40,939	2467.5	− 2528	−60.5	× 946 / 6666	−8.6
6	40,940	2471.9	− 2552	−80.1	× 946 / 6666	−11.4
7	40,941	2491.1	− 2567	−75.9	× 951 / 6666	−10.8
8	40,942	2501.5	− 2586	−84.5	× 1044 / 6666	−13.2
11	40,943	2528.3	− 2628	−99.7	× 869 / 6666	−13
Sum, rounded to a whole point						−67

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	39,868	2378.0	− 2436	−58	× 116 / 1197	−5.6
4	39,869	2434.9	− 2485	−50.1	× 120 / 1197	−5
5	39,870	2441.9	− 2528	−86.1	× 126 / 1197	−9.1
6	39,871	2436.3	− 2552	−115.7	× 176 / 1197	−17
7	39,872	2466.5	− 2567	−100.5	× 206 / 1197	−17.3
8	39,873	2449.9	− 2586	−136.1	× 220 / 1197	−25
11	39,874	2538.0	− 2628	−90	× 233 / 1197	−17.5
Sum, rounded to a whole point						−97

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	40,694	2389.4	− 2436	−46.6	× 821 / 6288	−6.1
4	40,695	2423.2	− 2485	−61.8	× 950 / 6288	−9.3
5	40,696	2443.7	− 2528	−84.3	× 873 / 6288	−11.7
6	40,697	2460.9	− 2552	−91.1	× 947 / 6288	−13.7
7	40,698	2479.0	− 2567	−88	× 916 / 6288	−12.8
8	40,699	2482.9	− 2586	−103.1	× 864 / 6288	−14.2
11	40,700	2499.7	− 2628	−128.3	× 917 / 6288	−18.7
Sum, rounded to a whole point						−87

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	40,731	2390.5	− 2436	−45.5	× 878 / 6271	−6.4
4	40,732	2429.1	− 2485	−55.9	× 840 / 6271	−7.5
5	40,733	2448.8	− 2528	−79.2	× 969 / 6271	−12.2
6	40,734	2457.2	− 2552	−94.8	× 872 / 6271	−13.2
7	40,735	2472.1	− 2567	−94.9	× 947 / 6271	−14.3
8	40,736	2478.2	− 2586	−107.8	× 930 / 6271	−16
11	40,737	2498.8	− 2628	−129.2	× 835 / 6271	−17.2
Sum, rounded to a whole point						−87

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	40,556	2384.5	− 2436	−51.5	× 886 / 6347	−7.2
4	40,557	2429.3	− 2485	−55.7	× 879 / 6347	−7.7
5	40,558	2447.1	− 2528	−80.9	× 864 / 6347	−11
6	40,559	2451.3	− 2552	−100.7	× 980 / 6347	−15.5
7	40,560	2476.8	− 2567	−90.2	× 898 / 6347	−12.8
8	40,561	2472.5	− 2586	−113.5	× 979 / 6347	−17.5
11	40,562	2495.2	− 2628	−132.8	× 861 / 6347	−18
Sum, rounded to a whole point						−90

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	40,339	2390.6	− 2436	−45.4	× 867 / 6331	−6.2
4	40,340	2425.5	− 2485	−59.5	× 888 / 6331	−8.3
5	40,341	2447.8	− 2528	−80.2	× 886 / 6331	−11.2
6	40,342	2448.8	− 2552	−103.2	× 877 / 6331	−14.3
7	40,343	2473.8	− 2567	−93.2	× 991 / 6331	−14.6
8	40,344	2484.4	− 2586	−101.6	× 913 / 6331	−14.7
11	40,345	2487.7	− 2628	−140.3	× 909 / 6331	−20.1
Sum, rounded to a whole point						−89

2026 from sb_ca2026_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	40,245	2384.7	− 2436	−51.3	× 879 / 6269	−7.2
4	40,246	2433.7	− 2485	−51.3	× 867 / 6269	−7.1
5	40,247	2449.5	− 2528	−78.5	× 883 / 6269	−11.1
6	40,248	2454.6	− 2552	−97.4	× 889 / 6269	−13.8
7	40,249	2473.9	− 2567	−93.1	× 875 / 6269	−13
8	40,250	2476.0	− 2586	−110	× 964 / 6269	−16.9
11	40,251	2506.3	− 2628	−121.7	× 912 / 6269	−17.7
Sum, rounded to a whole point						−87

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −72, −68, −69, −69, −67, −97, −87, −87, −90, −89, −87 → −80.2
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 4 · 2016→2017: 1 · 2017→2018: 0 · 2018→2019: 2 · 2019→2021: 30 · 2021→2022: 10 · 2022→2023: 0 · 2023→2024: 3 · 2024→2025: 1 · 2025→2026: 2 → average 5.3
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 5.3 × 2.66 = 14.1. Upper limit −66.1, lower limit −94.3.

Why 2.66? It is the standard factor from quality control, the work of Walter Shewhart and W. Edwards Deming. It turns "how much the result typically changes in a year" into "how far it can wander by chance alone".

Years with no result (no state tests were given in spring 2020) are skipped: the year-to-year change runs from the last year with a result to the next one.

Step 3 · Free or reduced-price meals

The share of enrolled students eligible for free or reduced-price meals — for a county, the total across its schools. From 2014–15, 2015–16, 2016–17, 2017–18, 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.