Question

( ) ( )
15 16.12
0.70
1.6
z
−
= ± = −
M1
P(Z < -0.70) = 1 - 0.7580 M1
= 0.2420 (awrt 0.242) A1
(3)

(b)
[P(T < t )=0.30 implies] z =
16.12
0.5244
1.6
t −
= −
M1 A1
16.12
0.5244
1.6
t −
= − ⇒ = − × t 16.12 1.6 "0.5244"
M1
t = awrt 15.28 (allow awrt 15.28/9)