Answer:
1.165.
Step-by-step explanation:
We have that to find our
level, that is the subtraction of 1 by the confidence interval divided by 2. So:

Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so 
Now, find the margin of error M as such

In which
is the standard deviation of the population and n is the size of the sample.
In this problem, we have that:
. So


So the correct answer is:
1.165.
Answer:
log(2)
Step-by-step explanation:
log(4) − log(2)
log(4/2)
log(2)
Answer:
C
Step-by-step explanation:
When we write an equation, we look for something like is or equals
A.twice as much as a number 2x
B.12 less than a number x-12
C.half of a number is 15 1/2x =15
D.the difference of 20 and a number? 20-x
A,B, and D are expressions
Right angle because that has 90 degree angle
Answer:
400 lb of salt
Step-by-step explanation:
Let us assume the water flows into the rank for x minutes.
There is an initial of 1000 gallons of water in the tank and water flows in through one pipe at 4 gal/min and through another pipe at 6 gal/min. In x minute, the amount of water in the tank = 1000 + 4x + 6x = 1000 + 10x
Water flows out at 5 gal/min, therefore in x minute the amount of water in the tank = 1000 + 10x - 5x = 1000 + 5x
The tank begins to overflow when it is full (has reached 1500 gallons). Therefore:
1500 = 1000 + 5x
5x = 1500 - 1000
5x = 500
x = 100 minutes.
1/2 lb salt per gallon flows into the tank at 4 gal/min and 1/3 lb of salt is flowing in at 6 gal/min, in 100 min the amount of salt that entered the tank = 4 gal/min × 100 min × 1/2 lb/gal + 6 gal/min × 100 min × 1/3 lb/gal= 400 lb
Therefore the amount of salt is in the tank when it is about to overflow = 400 lb of salt