Answer:



Step-by-step explanation:
For this case we have a confidence interval given as a percent:

If we express this in terms of fraction we have this:

We know that the confidence interval for the true proportion is given by:

And thats equivalent to:

We can estimate the estimated proportion like this:

And the margin of error can be estimaed using the fact that the confidence interval is symmetrical

And then the confidence interval in the form desired is:

Answer: 
Step-by-step explanation:
Let be "x" the time in minutes a 150-pound person must walk at 4 mph to use at least 190 calories.
The amount of calories that a 150-pound person uses in 1 minute when walking at a speed of 4 mph is:

Therefore, knowing this, we can write the following proportion:

Finally, we must solve for "x" in order to find its value.
Multiplying both sides of the equation by 190, we get this result:

The answer is 3.92%
Explanation
Do 2 divided by 51
0.03921
Multiply your answer by 100
3.9215
Round to the nearest tenth
3.92%
The answer is A cause the X represents the number of apples used in 1 cake and the 3 represents how much more apples it takes for the pie than the cake .