Question

QUESTION 1

I. The masses, to the nearest gram (g), of a random sample of 100 letters

passing through Montego Bay Post Office No. 1 is in the table below.

Mass (g)	40-59	60-69	70-79	80-89	90-99	100-149	150-159
Number of letters	10	25	46	6	5	4	4

    

Calculate to two decimal places:

a) the mean

b) the standard deviation

QUESTION 2

Research finds that of the students entering a degree

programme, 70% will successfully complete it. In 2018, 15

students commenced the course. Calculate the probability

that:

i. All 15 students will successfully complete the course.

ii. Only one student fails

iii. No more than two students fail.

iv. At least two students fail.

Answer 1

Range •F4Cmid) F [G-59 tb:: Ps (ets 8. 19-09 : S•อ 2: S- (t6 5-92 bd-98 S:48 6 9699 96.5 S 12.5 Lo0 - tk9 LSD-ISๆ f 4St.S :

To find mid-point of range M (x1 + x2) 2 To find grouped data mean E(M * F) и E(M * F) ΣF n To find grouped data variance 02 E(F* M2) - (n* u?) (n-1) To find grouped standard deviation = E(F* M2) - (n* u?) (n-1)

we get nean üs 763:11 Standard 2670 deviation of