Question 1139306
a. null hypothesis (H0): p = 0.62
   alternative hypothesis (H1): p>0.62
b. x ~ B(350,0.62)
let the critical value be k.
P(X≥k)<0.05
1-P(X≤k-1)<0.05
P(X≤k-1)<0.95
from the binomial cumulative calculator,
k-1=232
hence, k=233
c. critical region 233≤X≤350
acceptance region 0≤X≤232
d. since 238 lies in the critical region, the null hypothesis is REJECTED and there has been indeed an increase of cell phone users with 4G contract.