Answer:
The answer is "
".
Step-by-step explanation:
Calculating the critical value:
Freedom Degree= 7.
The significance level, 
Using excel function the critical value:

When
of the confidence intervals for the difference of means:
Alright, lets get started.
The ages of all four sisters will be = x, x+2, x+4, x+6
As per given in question, two times of youngest sister age exceeds the oldest sister age by 30 means

Simplifying the equation



So this is the age of youngest sister.
So, age of oldest sister will be 
Hene the age of oldest sister is 42 years. : Answer
Hope it will help :)
Answer:
sqrt. 65
Step-by-step explanation:
assuming that it is a right angle
7^2 + 4^2 = c^2
c=sqrt. 65
5500 is the awnser I came up with