Answer:
≈387,7
Step-by-step explanation:
I hope it's right. Sorry if it's not right.
Answer:
Option B is right
Step-by-step explanation:

(One tailed test at 5% significance level)
n =16 and x bar =1.97
s =0.1
Std error of mean = 
Mean diff = 
t statistic =Mean diff/se =-1.2
df =16-1=15
p value =0.124375
(B) do not reject the null because the test statistic (-1.2) is > the critical value (-1.7531).
u don't multiple u divide 3 and u do the same for 9 divide it by 3
21x and -6x. because they light terms.
i hope that help you