Answer:
Whats the question
Step-by-step explanation:
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
The exact value is
<span>sin<span>(arccos<span>(<span>3/4</span>)</span>)</span></span>The equation for cosine is <span>cos<span>(A)</span>=<span>AdjacentHypotenuse</span></span>. The inside trig function is <span>arccos<span>(<span>3/4</span>)</span></span>, which means <span>cos<span>(A)</span>=<span>3/4</span></span>. Comparing <span>cos<span>(A)</span>=<span>AdjacentHypotenuse</span></span> with <span>cos<span>(A)</span>=<span>3/4</span></span>, find <span>Adjacent=3</span> and <span>Hypotenuse=4</span>. Then, using the pythagorean theorem, find <span>Opposite=<span>√7</span></span>.<span>Adjacent=3</span><span>Opposite=<span>√7</span></span><span>Hypotenuse=4</span>Substitute in the known variables for the equation <span>sin<span>(A)</span>=<span>OppositeHypotenuse</span></span>.<span>sin<span>(A)</span>=<span><span>√7</span> over 4</span></span>Simplify.<span><span>√7</span><span> over 4</span></span>
Liza is wrong because...
Friday = 237
Saturday = 237 + 446
Both days = 920
