I hope I answer your question
Answer:
μ = 235.38
σ = 234.54
Step-by-step explanation:
Assuming the table is as follows:
![\left[\begin{array}{cc}Savings&Frequency\\\$0-\$199&339\\\$200-\$399&86\\\$400-\$599&55\\\$600-\$799&18\\\$800-\$999&11\\\$1000-\$1199&8\\\$1200-\$1399&3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7DSavings%26Frequency%5C%5C%5C%240-%5C%24199%26339%5C%5C%5C%24200-%5C%24399%2686%5C%5C%5C%24400-%5C%24599%2655%5C%5C%5C%24600-%5C%24799%2618%5C%5C%5C%24800-%5C%24999%2611%5C%5C%5C%241000-%5C%241199%268%5C%5C%5C%241200-%5C%241399%263%5Cend%7Barray%7D%5Cright%5D)
This is an example of grouped data, where a range of values is given rather than a single data point. First, find the total frequency.
n = 339 + 86 + 55 + 18 + 11 + 8 + 3
n = 520
The mean is the expected value using the midpoints of each range.
μ = (339×100 + 86×300 + 55×500 + 18×700 + 11×900 + 8×1100 + 3×1300) / 520
μ = 122400 / 520
μ = 235.38
The variance is:
σ² = [(339×100² + 86×300² + 55×500² + 18×700² + 11×900² + 8×1100² + 3×1300²) − (520×235.38²)] / (520 − 1)
σ² = 55009.7
The standard deviation is:
σ = 234.54
Answer:
see below
Step-by-step explanation:
The shading is below the line in both cases. The dashed line has negative slope, so the inequality associated with it is ...
y < -2x +4 . . . . . . note that the < symbol has no "or equal to"
The solid line has positive slope, so its inequality is ...
y ≤ 2x +4
Both these inequalities are found in choice B.
Answer:
Step-by-step explanation:
The idea here is to get the left side simplified down so it is the same as the right side. Consequently, there are 3 identities for cos(2x):
,
, and

We begin by rewriting the left side in terms of sin and cos, since all the identities deal with sines and cosines and no cotangents or cosecants. Rewriting gives you:

Notice I also wrote the 1 in terms of sin^2(x).
Now we will put the numerator of the bigger fraction over the common denominator:

The rule is bring up the lower fraction and flip it to multiply, so that will give us:

And canceling out the sin^2 x leaves us with just
which is one of our identities.