Answer: (30.49 years, 42.31 years)
Step-by-step explanation:
The formula to find the confidence interval is given by :-
, where = Sample mean
z* = Critical value.
= Population standard deviation.
n= Sample size.
As per given , we have
n= 40
We know that the critical value for 99% confidence interval : z* = 2.576 (By z-table)
A 99 percent confidence interval for µ, the true mean age of guests will be :
∴ a 99 percent confidence interval for µ, the true mean age of guests = (30.49 years, 42.31 years)
Answer:
Blue Bread cost a 1$ Silver Bread cost .50c
Blue dollar Siver 50 cent
Answer:
Step-by-step explanation:
i dont know what is it bro, you tell me
C = # of carpenter hrs , b = # of blacksmith hrs
c + b = 30...c = 30 - b
20c + 25b = 690
20(30 - b) + 25b = 690
600 - 20b + 25b = 690
-20b + 25b = 690 - 600
5b = 90
b = 90/5
b = 18 <== hrs worked as blacksmith
c + b = 30
c + 18 = 30
c = 30 - 18
c = 12 <== hrs worked as carpenter