Muir Elementary: 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.

2015 from sb_ca2015_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,817	2369.0	− 2436	−67	× 70 / 261	−18
4	10,819	2387.1	− 2485	−97.9	× 70 / 261	−26.3
5	10,821	2387.1	− 2528	−140.9	× 64 / 261	−34.6
6	10,823	2420.7	− 2552	−131.3	× 57 / 261	−28.7
Sum, rounded to a whole point						−107

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	9,834	2391.6	− 2436	−44.4	× 64 / 248	−11.5
4	9,836	2423.0	− 2485	−62	× 69 / 248	−17.3
5	9,838	2399.9	− 2528	−128.1	× 66 / 248	−34.1
6	9,840	2379.3	− 2552	−172.7	× 49 / 248	−34.1
Sum, rounded to a whole point						−97

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,162	2362.5	− 2436	−73.5	× 61 / 243	−18.5
4	10,165	2395.1	− 2485	−89.9	× 63 / 243	−23.3
5	10,166	2389.7	− 2528	−138.3	× 65 / 243	−37
6	10,169	2410.7	− 2552	−141.3	× 54 / 243	−31.4
Sum, rounded to a whole point						−110

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,181	2395.1	− 2436	−40.9	× 64 / 262	−10
4	10,183	2407.5	− 2485	−77.5	× 66 / 262	−19.5
5	10,185	2438.3	− 2528	−89.7	× 62 / 262	−21.2
6	10,187	2433.7	− 2552	−118.3	× 70 / 262	−31.6
Sum, rounded to a whole point						−82

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,261	2367.9	− 2436	−68.1	× 66 / 248	−18.1
4	10,262	2422.9	− 2485	−62.1	× 70 / 248	−17.5
5	10,263	2412.0	− 2528	−116	× 62 / 248	−29
6	10,264	2489.2	− 2552	−62.8	× 50 / 248	−12.7
Sum, rounded to a whole point						−77

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,254	2374.2	− 2436	−61.8	× 65 / 240	−16.7
4	10,255	2418.5	− 2485	−66.5	× 57 / 240	−15.8
5	10,256	2413.9	− 2528	−114.1	× 67 / 240	−31.9
6	10,257	2430.7	− 2552	−121.3	× 51 / 240	−25.8
Sum, rounded to a whole point						−90

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,242	2386.9	− 2436	−49.1	× 62 / 250	−12.2
4	10,243	2405.9	− 2485	−79.1	× 67 / 250	−21.2
5	10,244	2432.8	− 2528	−95.2	× 64 / 250	−24.4
6	10,245	2447.2	− 2552	−104.8	× 57 / 250	−23.9
Sum, rounded to a whole point						−82

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,208	2397.9	− 2436	−38.1	× 58 / 240	−9.2
4	10,209	2419.8	− 2485	−65.2	× 58 / 240	−15.8
5	10,210	2418.5	− 2528	−109.5	× 60 / 240	−27.4
6	10,211	2444.5	− 2552	−107.5	× 64 / 240	−28.7
Sum, rounded to a whole point						−81

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	10,185	2389.0	− 2436	−47	× 64 / 214	−14.1
4	10,186	2454.1	− 2485	−30.9	× 53 / 214	−7.7
5	10,187	2414.0	− 2528	−114	× 50 / 214	−26.6
6	10,188	2415.4	− 2552	−136.6	× 47 / 214	−30
Sum, rounded to a whole point						−78

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −107, −97, −110, −82, −77, −90, −82, −81, −78 → −89.3
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 10 · 2016→2017: 13 · 2017→2018: 28 · 2018→2019: 5 · 2019→2022: 13 · 2022→2023: 8 · 2023→2024: 1 · 2024→2025: 3 → average 10.1
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 10.1 × 2.66 = 26.9. Upper limit −62.4, lower limit −116.2.

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 2014–15, 2015–16, 2016–17, 2017–18, 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.