Answer:
Observational Study
Step-by-step explanation:
Because she stands by the front door and records each student
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.
Answer:
Step-by-step explanation:
The two x angles on the right are supplementary which means they add up to 180 degrees
5x + 12 + 7x - 24 = 180
12x - 12 = 180
12x = 192
x = 192/12
x = 18
5x + 12 and y are corresponding angles and are therefore equal
5(18) + 12 = 90 + 12 = 102
Therefore y = 102
Bear in mind that, when it comes to trigonometric functions, the location of the exponent can be a bit misleading, however recall that sin²(θ) is really [ sin( θ )]²,