Answer:
And we are 95% confident that the true mean of chloride concentration is between 0.375 and 0.377 cc/ cubic meter
Step-by-step explanation:
Data provided
represent the sample mean for the chloride concentration
population mean (variable of interest)
s=0.0012 represent the sample standard deviation
n=15 represent the sample size
Confidence interval
The confidence interval for the mean is given by the following formula:
(1)
Since we need to find the critical value first we need to begin finding the degreed of freedom
The Confidence is 0.95 or 95%, the significance would be
and
, and the critical value for this case with a t distribution with 14 degrees of freedom is
And the confidence interval is:
And we are 95% confident that the true mean of chloride concentration is between 0.375 and 0.377 cc/ cubic meter
Answer:
<em>6 days</em>
<em></em>
Step-by-step explanation:
Let the time taken by Carpenter working alone =
days
Then time taken by apprentice alone = Twice as that of taken by Carpenter = 2
days
Time taken working together = 2 days
Work done in one day working together = 
Work done in one day by Carpenter working alone = 
Work done in one day by apprentice working alone = 
Work done in one day by Carpenter working alone + Work done in one day by Carpenter working alone =
+
= Work done in one day working together = 

Time taken by Carpenter alone to complete the work = 3 days
Time taken by Apprentice alone to complete the work = 3
2= <em>6 days</em>
1. -2<2 2. -4> -5. -20<20. -7>-8. -10<-1. 50>-100
Answer:
384 cm²
Step-by-step explanation:
Since it is a square pyramid, the total surface area of the pyramid is the area of its square base plus the area of its 4 triangular faces.

Area of a triangular face
= ½ ×12 ×10
= 60 cm²

Base area of pyramid
= 12 ×12
= 144 cm²
∴ Surface area of pyramid
= 4(60) +144
= 240 +144
= 384 cm²
Answer:
REALS. all real numbers are solution for the equation
Step-by-step explanation:
for the equation
x² = (x + 3)*(x − 3) + 9
distributing the terms in the parenthesis
x² = (x + 3)*(x − 3) + 9 = [x² - 3*x + 3*x - 3*3 ] + 9
x² = x² - 9 + 9
0 = 0
since this statement will be true regardless of the value of x , then the equation has solution for all real numbers .