Consider this data set of ($\displaystyle {n}={117}$) birth weights in grams that has been sorted.

1630	1946	2049	2084	2111	2216	2219	2338	2389
2468	2506	2539	2547	2548	2570	2592	2599	2636
2664	2674	2690	2693	2754	2766	2785	2840	2843
2844	2882	2891	2903	2909	2914	2929	2957	2985
3001	3005	3022	3028	3032	3062	3073	3079	3082
3105	3106	3111	3118	3156	3174	3182	3194	3224
3227	3234	3242	3250	3252	3274	3280	3313	3336
3351	3351	3356	3409	3412	3418	3421	3425	3437
3458	3459	3465	3470	3488	3494	3513	3516	3520
3537	3573	3603	3653	3660	3671	3671	3709	3714
3725	3735	3739	3749	3761	3761	3780	3850	3853
3873	3888	3920	3955	3963	3978	3995	4071	4123
4137	4150	4167	4199	4240	4260	4579	4688	4783

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Use a spreadsheet to find the 20-Percentile:
P₂₀ =