Answer:
Lillian worked 7h and Jacob worked 6h
Step-by-step explanation:
the number of hours Lillian worked are x (h)
the number of hours Jacob worked are y (h)
(0 < x,y < 13)
=> Lilian ironed: 25x (shirts)
Jacob ỉroned: 20y (shirts)
because Lillian and Jacob worked a combined 13 hours and ironed 295 shirts, we have:
so Lillian worked 7h and Jacob worked 6h
Answer:
a)0.6192
b)0.7422
c)0.8904
d)at least 151 sample is needed for 95% probability that sample mean falls within 8$ of the population mean.
Step-by-step explanation:
Let z(p) be the z-statistic of the probability that the mean price for a sample is within the margin of error. Then
z(p)= where
a.
z(p)= ≈ 0.8764
by looking z-table corresponding p value is 1-0.3808=0.6192
b.
z(p)= ≈ 1.1314
by looking z-table corresponding p value is 1-0.2578=0.7422
c.
z(p)= ≈ 1.6
by looking z-table corresponding p value is 1-0.1096=0.8904
d.
Minimum required sample size for 0.95 probability is
N≥ where
then N≥ ≈150.6
Thus at least 151 sample is needed for 95% probability that sample mean falls within 8$ of the population mean.