Answer:
Dan
Step-by-step explanation:
Ella has only 65 photos, while Dan has 78.
78 is a higher number than 65...
Answer:
Nerys pays 3.1/3.84,5=84,5£per year
Eleri pays 3.84,5=253,5£per year
253,5-84,5=169£ more pay Eleri
That's a quadratic, a nice parabola in vertex form.
The parabola has a positive x^2 term, so it's a CUP, concave up positive. It will have a minimum at the vertex, which is (2,5). Plot that point.
Now we need a couple of guide points to draw the usual parabola going up from both sides of its vertex. We try x=0 giving (0,9) and see that x=4 also gives 9, (4,9). Plot the parabola through those two points and the vertex and you're done.
Answer:

From this result we can conclude that the value of 70.9 is 0.78 deviation below the true mean of 71.5 and that can be considered as unusual. If we conduct a hypothesis test or a confidence interval we will see that we have enough evidence to conclude that the true mean is not significantly different from 71.5.
Step-by-step explanation:
For this case from all the population we know that the population mean and deviation are:

And we take a random sample of size n =40 and we got a sample mean calculated with the following formula:

And we want to test if this value is unusually low.
Since the sample size is large n>30 we can use the central limit theorem who says that the distribution for the sample mean is given by:

And on this case if we replace the values that we have we got:

For this case we can calculate how many deviations above or below is our calculated value from the sample of size 40, using the z score given by:

From this result we can conclude that the value of 70.9 is 0.78 deviation below the true mean of 71.5 and that can be considered as unusual. If we conduct a hypothesis test or a confidence interval we will see that we have enough evidence to conclude that the true mean is not significantly different from 71.5.