Answer: point estimate = 3.88
Margin of error = 0.63
Step-by-step explanation:
Confidence interval is written in the form,
(Point estimate - margin of error, Point estimate + margin of error)
The sample mean, x is the point estimate for the population mean. Let m represent the margin of error. Since the confidence interval is given as (3.25 , 4.51), it means that
x - m = 3.25
x + m = 4.51
Adding both equations, it becomes
2x = 7.76
x = 7.76/2
x = 3.88
Substituting x = 3.88 into x + m = 4.51, it becomes
3.88 + m = 4.51
m = 4.51 - 3.88
m = 0.63
You can find the numerical part of the answer because it is the same on the right side.
For example:
¹ <<==== Regrouped
89
+
67
---------
146 <<=== I had to press space so I could position it.
So that also happens in subtraction, the left side can be found by doing the same steps in the right column.
For example:
67
- <<=== this time there was no regrouping
12
-------
55
Answer:
Step-by-step explanation:
8 in × (1 ft)/(12 in) = ⅔ ft
36 ft × 58 ft × ⅔ ft = 1392 ft³
1392 ft³ × (1 yd³)/(27 ft³) ≅ 52 yd³
52 yd³ × $123/yd³ = $6396
Answer:
Step-by-step explanation:
For quite some time now, calculators have had statistical functions built in. Here we need to use the stat. function normalcdf, which has only two inputs when we're working with z scores instead of raw scores.
Here,
normalcdf(-100,1.25) = 0.894
This same result could be obtained using a table of z-scores.
