1 a)The mean time to assemble a product as found from a sample of size 40 is 10.4 minutes. The standard deviation of the assembly times is known to be 1.2 minutes. The manager in charge of the assembly line believes that the mean assembly time is less than 10.8 min. Can he make this conclusion at a significance level of 0.05?

1 b)This table contains data on three variables that were collected in an observational study in a semiconductor manufacturing plant. In this plant, the finished semiconductor is wire bonded to a frame. The variables reported are pull strength (a measure of the amount of force required to break the bond), the wire length, and the height of the die. We would like to find a relation between pull strength to wire length and die height.

Observation	Pull Strength	Wire length	Die Height
1	9.95	2	50
2	24.45	8	110
3	31.75	11	120
4	35	10	550
5	25.02	8	295
6	16.86	4	200
7	14.38	2	375
8	9.6	2	52
9	24.35	9	100
10	27.5	8	300
11	17.08	4	412
12	37	11	400
13	41.95	12	500
14	11.66	2	360
15	21.65	4	205
16	17.89	4	400
17	69	20	600
18	10.3	1	585
19	34.93	10	540
20	46.59	15	250
21	44.88	15	290
22	54.12	16	510
23	56.63	17	590
24	22.13	6	100
25	21.15	5	400

Construct a matrix plot and make comments on the relationship between the variables. (5M