Answer:
A sample of 179 is needed.
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 
.
That is z with a pvalue of 
, so Z = 1.44.
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.
A previous study found that for an average family the variance is 1.69 gallon?
This means that 
If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?
A sample of n is needed, and n is found for M = 0.14. So
Rounding up
A sample of 179 is needed.
-4,. 3
or. ±4/1,. ±2/1,. ±1/1,. ±4/3,. ±2/3,. ±1/3,.
Answer:
3 gallons I am in math club believe it or not
Answer:
You can measure the area of the yard but measuring the length and width and then multiplying. Then you can divide by the amount of sod that is used to cover to see how many bags that need to be bought.
Step-by-step explanation:
This should be good :)
pls mark brainliest:)
Answer: The distance between the girls is 362.8 meters.
Step-by-step explanation:
So we have two triangle rectangles that have a cathetus in common, with a length of 160 meters.
The adjacent angle to this cathetus is 40° for Anna, then the opposite cathetus (the distance between Anna and the tower) can be obtained with the relationship:
Tan(A) = opposite cath/adjacent cath.
Tan(40°) = X/160m
Tan(40°)*160m = 134.3 m
Now, we can do the same thing for Veronica, but in this case the angle adjacent to the tower is 55°
So we have:
Tan(55°) = X/160m
Tan(55°)*160m = X = 228.5 m
And we know that the girls are in opposite sides of the tower, so the distance between the girls is equal to the sum of the distance between each girl and the tower, then the distance between the girls is:
Dist = 228.5m + 134.3m = 362.8m
