Answer:
C. two real solutions
Step-by-step explanation:
Your quadratic matches the form ...
ax^2 +bx +c = 0
for the values a=2, b=7, c=-15.
The discriminant is ...
d = b^2 -4ac
For your values of a, b, c, the discriminant value is ...
d = 7^2 -4(2)(-15) = 169
The discriminant is positive, indicating there are two real solutions.
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When the discriminant is negative, there are no real solutions, only complex solutions.
When the discriminant is zero, there is one real solution.
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This equation factors as (2x-3)(x+5) = 0 and has solutions x=3/2, x=-5.
Answer:
(a) Mean = 587
Median = 585
Mode = 590
Standard deviation = 112.54
(b) Mean and median are both appropriate as they are close in value, suggesting that the data is quite symmetric.
Explanation:
All four measures are calculated by inserting simple formulas in Excel. These are shown in the below screenshot of the work file.
Answer:
Sin 90°=1
Step-by-step explanation:
A unit circle is a circle with a radius of 1 .Because the radius is 1, it is possible to directly measure the sine, cosine and tangent.
<em>using the unit circle where 90° is the limit as the hypotenuse approaches the vertical y-axis which is positive.</em>
Sine=opposite/hypotenuse
Sin=O/H
<u>Applying the limits</u>
Sine 90°=1/1= 1
cos 90° =0/1 =0
or
When the angle formed at the origin of the unit circle in the 1st quadrant is 0°, cos 0°=1 sin0°=0 and tan 0°=0
When we increase the angle until it is 90°, cos 90°=0, sin 90°=1 and tan 90°=undefined
Answer: C) Survey a random sample of persons within each neighborhood of the city.
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Explanation:
I'll go through each answer choice to say why it is either the answer or not the answer.
A. This is not the answer because teachers are over-represented while non-teachers are under-represented. The teachers will most likely respond favorably to the survey, skewing the results. The other townspeople's opinions would be left out.
B. This is not the answer because people living far away from the city in question should not have sway over what happens in the particular city. It makes no sense to have someone in San Francisco determine what happens in LA schools. It's better to ask people who live in the city. Perhaps you could extend the net to nearby surrounding cities assuming those parents commute into the city to drop off their kids at those schools.
C. This is the answer. It's best to ask city residents because it is a local city issue. I would put every resident's name or address into a computer database, then have a random number generator select those individuals.
D. This is not the answer. People who do not visit city hall will not be represented at all, which skews the results of what the people of the city want overall.
