The probability of an event can be defined as the long-term proportion of times that it occurs when the experiment is repeated. Unfortunately, although this explains the concept of the event's probability, it does not provide a numerical value in practice — the experiment cannot be repeated an infinite number of times.

However although we cannot repeat the experiment an infinite number of times, the proportion of times that the event occurs in a large number of repetitions will give an approximate value for the probability — an estimate of its value.

Survival of silkworm larvae

From the following data set, estimate the probability that a silkworm will survive at least 300 seconds.

Survival of poisoned silkworm larvae (seconds)
270
254
293
244
293
261
285
330
284
274
307
235
215
292
309
267
275
298
241
254
256
275
226
287
280
339
294
298
283
366
300
310
280
240
291
286
230
285
218
279
280
286
345
289
210
282
260
228
243
259
285
275
280
296
283
248
314
258
215
299
240
241
236
255
267
271
253
271
233
260
273
233
271
267
258
319
310
302
260
251

(Solved in full version)