a seagull flying over a lake drops a fish from 81 feet. after about how many secomds does the fish land in the water?

What are the x-intercepts of the function f(x) = –2x2 – 3x + 20?

Hatshy [7]

The root sof this quadratic equation are -4 and 2.5.

The roots of any quadratic can be found by using the quadratic equation. The equation is below for you.

$\frac{-b +/- \sqrt{b^{2}- 4ac}}{2a}$

In this equation you use the number attached to x^2 as the a, which in this case is -2. The number attached to x as b, which is in this case -3. And the number at the end as c, which is 20. From there you solve for the answers.

$\frac{3 +/- \sqrt{-3^{2}- 4(-2)(20)}}{2(-2)}$

$\frac{3 +/- \sqrt{9 + 160}}{-4}$

$\frac{3 +/- 13}}{4}$

Now you separate and get the two separate answers. First the positive.

$\frac{3 + 13}}{4}$

$\frac{16}}{4}$

4

Now the negative

$\frac{3 - 13}}{4}$

$\frac{-10}}{4}$

-2.5

5 0

2 years ago

Read 2 more answers

During a 5-kilometer run to raise money for the school band, Tabitha ran 0.08 kilometer per

Thepotemich [5.8K]

Answer:

True

0.08 km/ 1 min = 1 mi = 1.61 km

answer rounds to 0.05

7 0

2 years ago

Direct Mailing Company sells computers and computer parts by mail. The company claims that more than 90% of all orders are maile

lys-0071 [83]

Answer:

We conclude that less than or equal to 90% of all orders are mailed within 72 hours after they are received which means the company's claim is not true.

Step-by-step explanation:

We are given that the company claims that more than 90% of all orders are mailed within 72 hours after they are received. The quality control department at the company often takes samples to check if this claim is valid.

A recently taken sample of 175 orders showed that 161 of them were mailed within 72 hours.

Let p = percentage of all orders that are mailed within 72 hours.

SO, Null Hypothesis, $H_0$ : p $\leq$ 90% {means that less than or equal to 90% of all orders are mailed within 72 hours after they are received}

Alternate Hypothesis, $H_A$ : p > 90% {means that more than 90% of all orders are mailed within 72 hours after they are received}

The test statistics that will be used here is One-sample z proportion statistics;

T.S. = $\frac{\hat p-p}{{\sqrt{\frac{\hat p(1-\hat p)}{n} } } } }$ ~ N(0,1)

where, $\hat p$ = proportion of orders that were mailed within 72 hours in a sample of 175 = $\frac{161}{175}\times 100$ = 92%

n = sample of orders = 175

So, test statistics = $\frac{0.92-0.90}{{\sqrt{\frac{0.92(1-0.92)}{175} } } } }$

= 0.975

The value of the test statistics is 0.975.

Now at 1% significance level, the z table gives critical value of 2.3263 for right-tailed test. Since our test statistics is less than the critical value of z as 0.975 < 2.3263, so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region due to which we fail to reject our null hypothesis.

Therefore, we conclude that less than or equal to 90% of all orders are mailed within 72 hours after they are received which means the company's claim is not true.

6 0

2 years ago

Compare the functions shown below: f(x) = 4x + 5 g(x) tangent function with y intercept at 0, 2 h(x) = 3 sin(2x + π) − 2 Which f

KATRIN_1 [288]

The y-intercept of the graph of a function is the value of f(0) for any function f.
That is, it is the y-value in the pair (0, y)

The y-intercept of f(x) = 4x + 5 is f(0)=4*0+5=5

The y-intercept of (0, 2) is 2.

The y-intercept of h(x) = 3 sin(2x + π) − 2 is:

h(0) = 3 sin(2*0 + π) − 2=3 sin(π) − 2=3*0-2=-2

Answer: The function f has the greatest y-intercept.

7 0

2 years ago

A recent study found that 51 children who watched a commercial for Walker Crisps (potato chips) featuring a long-standing sports

hichkok12 [17]

Answer:

1

The claim is that the mean amount of Walker Crisps eaten was significantly higher for the children who watched the sports celebrity- endorsed Walker Crisps commercial

2

The kind of test to use is a t -test because a t -test is used to check if there is a difference between means of a population

3

$t = 3.054$

4

The p-value is $p-value = P(Z > 3.054) = 0.0011291$

5

The conclusion is

There is sufficient evidence to conclude that the mean amount of Walker Crisps eaten was significantly higher for the children who watched the sports celebrity- endorsed Walker Crisps commercial

The test statistics is

Step-by-step explanation:

From the question we are told that

The first sample size is $n_1 = 51$

The first sample mean is $\mu_1 = 36$

The second sample size is $n_2 = 41$

The second sample size is $\mu_2 = 25$

The first standard deviation is $\sigma _1 = 21.4 \ g$

The second standard deviation is $\sigma _2 = 12.8 \ g$

The level of significance is $\alpha = 0.05$

The null hypothesis is $H_o : \mu_1 = \mu_ 2$

The alternative hypothesis is $H_a : \mu_1 > \mu_2$

Generally the test statistics is mathematically represented as

$t = \frac{\= x_1 - \= x_2}{ \sqrt{ \frac{s_1^2}{n_1} + \frac{s_2^2}{n_2} } }$

=> $t = \frac{ 36 - 25}{ \sqrt{ \frac{ 21.4^2}{51} + \frac{ 12.8^2}{41} } }$

=> $t = 3.054$

The p-value is mathematically represented as

$p-value = P(Z > 3.054)$

Generally from the z table

$P(Z > 3.054) = 0.0011291$

=> $p-value = P(Z > 3.054) = 0.0011291$

From the values obtained we see that $p-value < \alpha$ so the null hypothesis is rejected

Thus the conclusion is

There is sufficient evidence to conclude that the mean amount of Walker Crisps eaten was significantly higher for the children who watched the sports celebrity- endorsed Walker Crisps commercial

5 0

2 years ago