Mojave River Academy - National Trails: math

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.

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
6	64,253	2416.5	− 2552	−135.5	× 12 / 211	−7.7
7	64,254	2432.0	− 2567	−135	× 35 / 211	−22.4
8	64,255	2440.9	− 2586	−145.1	× 47 / 211	−32.3
11	64,256	2470.4	− 2628	−157.6	× 117 / 211	−87.4
Sum, rounded to a whole point						−150

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	64,323	2323.0	− 2436	−113	× 12 / 279	−4.9
4	64,324	2386.8	− 2485	−98.2	× 15 / 279	−5.3
5	64,325	2377.5	− 2528	−150.5	× 17 / 279	−9.2
6	64,326	2432.4	− 2552	−119.6	× 25 / 279	−10.7
7	64,327	2418.9	− 2567	−148.1	× 26 / 279	−13.8
8	64,328	2428.6	− 2586	−157.4	× 28 / 279	−15.8
11	64,329	2453.1	− 2628	−174.9	× 156 / 279	−97.8
Sum, rounded to a whole point						−157

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	64,306	2291.3	− 2436	−144.7	× 13 / 322	−5.8
5	64,308	2382.0	− 2528	−146	× 21 / 322	−9.5
6	64,309	2366.2	− 2552	−185.8	× 31 / 322	−17.9
7	64,310	2411.6	− 2567	−155.4	× 36 / 322	−17.4
8	64,311	2408.7	− 2586	−177.3	× 49 / 322	−27
11	64,312	2448.4	− 2628	−179.6	× 172 / 322	−95.9
Sum, rounded to a whole point						−174

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	64,280	2317.4	− 2436	−118.6	× 17 / 372	−5.4
4	64,281	2352.5	− 2485	−132.5	× 16 / 372	−5.7
5	64,282	2377.7	− 2528	−150.3	× 14 / 372	−5.7
6	64,283	2365.4	− 2552	−186.6	× 39 / 372	−19.6
7	64,284	2405.9	− 2567	−161.1	× 54 / 372	−23.4
8	64,285	2418.6	− 2586	−167.4	× 65 / 372	−29.3
11	64,286	2433.1	− 2628	−194.9	× 167 / 372	−87.5
Sum, rounded to a whole point						−176

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	64,044	2335.9	− 2436	−100.1	× 21 / 401	−5.2
4	64,045	2378.0	− 2485	−107	× 20 / 401	−5.3
5	64,046	2360.5	− 2528	−167.5	× 13 / 401	−5.4
6	64,047	2401.0	− 2552	−151	× 41 / 401	−15.4
7	64,048	2399.5	− 2567	−167.5	× 63 / 401	−26.3
8	64,049	2414.3	− 2586	−171.7	× 83 / 401	−35.5
11	64,050	2433.6	− 2628	−194.4	× 160 / 401	−77.6
Sum, rounded to a whole point						−171

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −150, −157, −174, −176, −171 → −165.6
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2019→2022: 7 · 2022→2023: 17 · 2023→2024: 2 · 2024→2025: 5 → average 7.8
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 7.8 × 2.66 = 20.7. Upper limit −144.9, lower limit −186.3.

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