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3 years ago

The coefficients of a, b, and c in the following quadratic equation are a = 4, b = 4, and c = -1:

Mathematics

1 answer:

iVinArrow [24]3 years ago

5 0

if c is -1 the equation should be

4x² + 4x -1 = 0

not plus 1

I assume you want the coordinates of the zeros.

if c is indeed -1, they are at (-1.207 , 0) and (0.207 , 0)

if c is +1, as in the equation the only zero point is at (-0.5 , 0)

see screenshot for illustration

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One more question 50 points

balu736 [363]

Answer:

5 complete scarves

Step-by-step explanation:

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3 years ago

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Consider the probability that greater than 94 out of 153 people will not get the flu this winter. Assume the probability that a

Hatshy [7]

Answer:

0.8212 = 82.12% probability that greater than 94 out of 153 people will not get the flu this winter.

Step-by-step explanation:

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$p = 0.65, n = 153$ . So

$\mu = E(X) = 153*0.65 = 99.45$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{153*0.65*0.35} = 5.9$

Consider the probability that greater than 94 out of 153 people will not get the flu this winter

This probability is 1 subtracted by the pvalue of Z when X = 94. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{94 - 99.45}{5.9}$

$Z = -0.92$

$Z = -0.92$ has a pvalue of 0.1788

1 - 0.1788 = 0.8212

0.8212 = 82.12% probability that greater than 94 out of 153 people will not get the flu this winter.

7 0

3 years ago

A french fry stand at the fair serves their fries in paper cones. The cones have a radius of 22 inches and a height of 66 inches

icang [17]

Answer:

The height of the new cones will be 16.5 inches.

Step-by-step explanation:

We know that,

The volume of a cone is,

$V=\frac{1}{3}\pi r^2 h$

Where, r is the radius of the cone,

h is the height of the cone,

In the original cone,

r = 22 inches,

h = 66 inches,

Thus, the volume would be,

$V_1=\frac{1}{3}\pi (22)^2(66)$

Also, for the new cone,

r = 44 inches,

Let H be the height,

So, the volume of the new cone would be,

$V_2=\frac{1}{3}\pi (44)^2(H)$

According to the question,

$V_2=V_1$

$\implies \frac{1}{3}\pi (44)^2(H)=\frac{1}{3}\pi (22)^2(66)$

$\implies H=\frac{22^2(66)}{44^2}=(\frac{22}{44})^2\times 66 = \frac{66}{4}=16.5$

Hence, the height of the new cones will be 16.5 inches.

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3 years ago

The price of tickets for the dance was 1 ticket for $6 or 2 tickets for $8 she looked inside the cash box and found $200 and tic

Aleks04 [339]

We can say that exchanging one couple's ticket for an individual's ticket would increase the money in the cash box from 200 to 202 and it would result in an even number of couples tickets sold.

<u>Step-by-step explanation:</u>

Let the number of tickets sold to the individuals = s

Let the number of tickets sold to the couples = c

According to the question,

s + c = 46 ( Equation 1)

Since each individual's ticket is $6, the total amount of money made by selling tickets to individuals is 6s.

Similarly, since each ticket sold to couples is $8, the total amount of money made by selling tickets to couples is 8c.

So,

6 s + 8 c = 200 ( Equation 2)

On solving both the equations, we get

c = 38 and s = 8

Therefore, 8 tickets were sold to individuals and 38 tickets were sold to the couples.

5 0

3 years ago

Henri bought a swim suit at a cost of $8. Which statements are true regarding the cost of the suit? Check all that apply.

kolezko [41]

If the selling price is marked up by 25 percent, the new price will be $10.
8 * 1.25 = 10
If the selling price is marked up by 70 percent, the new price will be $13.60.
8 * 1.70 = 13.6
If the selling price is marked up by 75 percent, the new price will be $14.
8 * 1.75 = 14

3 0

3 years ago

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