Inference: practice

A regional train operator brought in a new timetable in March. In the three months before the change, 71% of its trains arrived within five minutes of schedule. In the three months after the change, 88% did. The operator ran the same number of trains, on the same lines, in each of the two periods, and no other operator in the region changed its timetable.

Complaints to the operator about delays fell by almost half after March.

Question 1

Proposed inferenceMore of the operator's trains arrived within five minutes of schedule in the three months after the change than in the three months before.

Question 2

Proposed inferenceThe new timetable contributed to the improvement in punctuality.

Question 3

Proposed inferenceThe number of complaints the operator received about delays roughly halved after March.

Question 4

Proposed inferencePunctuality on the operator's trains was worse after March than before it.

Question 5

Proposed inferenceThe operator raised its fares in March.

Brightwell has one secondary school, with 600 pupils. Last year the school started a homework club that runs every weekday from the end of lessons until 5 pm. Attendance is voluntary.

Teachers recorded that 140 pupils attended the club at least once in the autumn term. Pupils who attended at least ten sessions handed in, on average, more homework on time than pupils who never attended.

Question 6

Proposed inferenceFewer than a quarter of the school's pupils attended the homework club at least once in the autumn term.

Question 7

Proposed inferenceMost of the school's pupils attended the homework club at least once in the autumn term.

Question 8

Proposed inferenceTeachers are paid extra to run the homework club.

A logistics firm surveyed its 450 warehouse employees about working hours, and 412 replied. Of those who replied, 380 said they would prefer a four-day week of longer shifts to the current five-day week.

The firm's directors will decide the matter next month and have said that staff wishes will carry a lot of weight. The firm's lawyers have checked every one of the warehouse's customer contracts and found that none of them would be broken by a four-day week.

Question 9

Proposed inferenceMost of the firm's warehouse employees prefer a four-day week.

Question 10

Proposed inferenceThe directors will introduce a four-day week at the warehouse.

Question 11

Proposed inferenceEvery employee who replied to the survey wanted to keep the five-day week.

Question 12

Proposed inferenceThe firm's office staff were also asked about a four-day week.

Question 13

Proposed inferenceMoving the warehouse to a four-day week would break at least one customer contract.

In January, Marsh Lane Library began opening until 8 pm on Tuesdays and Thursdays instead of closing at 5 pm. In February, it counted 1,900 visits on Tuesday and Thursday evenings after 5 pm.

Total monthly visits rose from about 9,000 in December to about 11,500 in February. The library did not change any of its other opening hours or run any special events in either month.

Question 14

Proposed inferenceThe library received more visits in February than in December.

Question 15

Proposed inferenceVisits after 5 pm on Tuesdays and Thursdays made up more than half of all visits in February.

Question 16

Proposed inferenceThe later opening brought in some visits that would not otherwise have happened.

Question 17

Proposed inferenceThe library's staff costs fell between December and February.

Question 18

Proposed inferenceThe library opens on Sundays.

A clinic ran a six-week trial of an online booking system. During the trial, patients could book an appointment either online or by phone, and 62% of all bookings were made online. Of bookings made by patients aged over 75, 9% were made online.

The clinic's phone line received 30% fewer calls than in the same six weeks of the previous year. The number of patients registered with the clinic did not change.

Question 19

Proposed inferenceDuring the trial, most bookings were made online.

Question 20

Proposed inferenceDuring the trial, most bookings by patients aged over 75 were made by phone.

Question 21

Proposed inferenceThe online system reduced the number of calls to the clinic's phone line.

Question 22

Proposed inferenceEvery booking made by a patient aged over 75 during the trial was made by phone.

A city council planted 600 street trees in the spring, about half of them in streets where residents had signed up to water the trees through the summer.

By the end of the first summer, 45 of the trees had died: 40 in streets where no residents had signed up, and 5 in streets where residents had.

Question 23

Proposed inferenceMost of the trees that died were in streets where no residents had signed up to water them.

Question 24

Proposed inferenceResidents' watering helped more of the trees survive the first summer.

Question 25

Proposed inferenceMore than one in ten of the trees planted died in the first summer.

Question 26

Proposed inferenceAll the trees that died were of the same species.

In April, Northfield Tennis Club raised its annual membership fee from £180 to £240. In the two months after the rise, 35 of its 260 members did not renew, compared with an average of 10 non-renewals in the same two months over the previous five years.

The club's committee had promised to resurface all six courts using the extra income.

Question 27

Proposed inferenceMore members than usual did not renew in the two months after the fee rise.

Question 28

Proposed inferenceThe fee rise led some members not to renew.

Question 29

Proposed inferenceThe membership fee rose by more than a third.

Question 30

Proposed inferenceAll six courts at the club had already been resurfaced by the time of the fee rise.

Question 31

Proposed inferenceNorthfield is the only tennis club in its town.