Redding Collegiate Academy: english

The shaded band is this school'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.

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	87,016	2382.5	− 2432	−49.5	× 11 / 66	−8.3
5	87,020	2476.6	− 2502	−25.4	× 14 / 66	−5.4
6	87,021	2467.6	− 2531	−63.4	× 11 / 66	−10.6
7	87,024	2523.0	− 2552	−29	× 12 / 66	−5.3
8	87,025	2586.1	− 2567	19.1	× 18 / 66	5.2
Sum, rounded to a whole point						−24

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
4	87,626	2409.7	− 2473	−63.3	× 12 / 81	−9.4
5	87,627	2486.0	− 2502	−16	× 11 / 81	−2.2
6	87,628	2481.2	− 2531	−49.8	× 11 / 81	−6.8
7	87,629	2519.7	− 2552	−32.3	× 24 / 81	−9.6
8	87,630	2537.7	− 2567	−29.3	× 23 / 81	−8.3
Sum, rounded to a whole point						−36

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	87,979	2523.9	− 2531	−7.1	× 12 / 91	−0.9
7	87,980	2553.0	− 2552	1	× 21 / 91	0.2
8	87,981	2526.3	− 2567	−40.7	× 31 / 91	−13.9
11	87,982	2606.9	− 2583	23.9	× 27 / 91	7.1
Sum, rounded to a whole point						−7

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	87,896	2502.4	− 2531	−28.6	× 12 / 95	−3.6
7	87,897	2563.3	− 2552	11.3	× 19 / 95	2.3
8	87,898	2552.7	− 2567	−14.3	× 31 / 95	−4.7
11	87,899	2562.0	− 2583	−21	× 33 / 95	−7.3
Sum, rounded to a whole point						−13

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
5	87,876	2519.9	− 2502	17.9	× 12 / 98	2.2
6	87,877	2549.1	− 2531	18.1	× 11 / 98	2
7	87,878	2578.3	− 2552	26.3	× 13 / 98	3.5
8	87,879	2579.3	− 2567	12.3	× 26 / 98	3.3
11	87,880	2532.4	− 2583	−50.6	× 36 / 98	−18.6
Sum, rounded to a whole point						−8

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	87,566	2436.3	− 2432	4.3	× 15 / 111	0.6
5	87,568	2516.5	− 2502	14.5	× 12 / 111	1.6
6	87,569	2505.8	− 2531	−25.2	× 14 / 111	−3.2
7	87,570	2607.5	− 2552	55.5	× 19 / 111	9.5
8	87,571	2581.2	− 2567	14.2	× 17 / 111	2.2
11	87,572	2589.3	− 2583	6.3	× 34 / 111	1.9
Sum, rounded to a whole point						13

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −24, −36, −7, −13, −8, 13 → −12.5
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2018→2019: 12 · 2019→2022: 29 · 2022→2023: 6 · 2023→2024: 5 · 2024→2025: 21 → average 14.6
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 14.6 × 2.66 = 38.8. Upper limit 26.3, lower limit −51.3.

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. From 2017–18, 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.