PLEASEEEEE HELP!!!!

If a cyclist increases his speed by 3 miles per hour, he can reduce the time required for a 6 mile trip by 10 minutes. What is t

raketka [301]

Answer:

Slower speed = 9 mph

Step-by-step explanation:

Let the initial speed (slower speed) = s mph

Speed 's' = $\frac{\text{Distance}}{\text{Time}}$

s = $\frac{6}{t}$ -------(1)

If the cyclist increases the speed by 3 mph then the final speed = (s + 3) mph

He can reduce the time 't' by 10 minutes ( $\frac{1}{6}$ hours)

Now, (s + 3) = $\frac{6}{t-\frac{1}{6}}$

s + 3 = $\frac{36}{6t-1}$ --------(2)

Substitute the value of 's' from equation (1) to the equation (2).

$\frac{6}{t}+3=\frac{36}{6t-1}$

$\frac{2}{t}+1=\frac{12}{6t-1}$

$\frac{2}{t}-\frac{12}{6t-1}=-1$

$\frac{2(6t-1)-12t}{t(6t-1)}=-1$

$\frac{12t-2-12t}{t(6t-1)}=-1$

$-\frac{2}{t(6t-1)}=-1$

6t² - t = 2

6t² - t - 2 = 0

6t² - 4t + 3t - 2 = 0

2t(3t - 2) + 1(3t - 2) = 0

(2t + 1)(3t - 2) = 0

t = $-\frac{1}{2},\frac{2}{3}$ hours

But the time can't be negative.

Therefore, t = $\frac{2}{3}$ hours is the answer.

From equation (1),

s = $\frac{6}{\frac{2}{3}}$

s = 9 miles per hour.

Slower speed = 9 mph is the answer.

6 0

3 years ago

What is the areas of triangle

SashulF [63]

135 is the answer hope this helps

6 0

3 years ago

The National Transportation Safety Board publishes statistics on the number of automobile crashes that people in various age gro

ra1l [238]

Answer:

a) Null hypothesis: $p\leq 0.12$

Alternative hypothesis: $p > 0.12$

b) $z_{\alpha}=1.64$

c) $z=\frac{0.134 -0.12}{\sqrt{\frac{0.12(1-0.12)}{1000}}}=1.362$

d) $p_v =P(z>1.362)=0.0866$

e) For this case since the statistic is lower than the critical value and the p value higher than the significance level we have enough evidence to FAIL to reject the null hypothesis so then we don't have information to conclude that the true proportion is higher than 0.12

Step-by-step explanation:

Information given

n=1000 represent the random sample selected

X=134 represent the number of young drivers ages 18 – 24 that had an accident

$\hat p=\frac{134}{1000}=0.134$ estimated proportion of young drivers ages 18 – 24 that had an accident

$p_o=0.12$ is the value that we want to verify

$\alpha=0.05$ represent the significance level

Confidence=95% or 0.95

z would represent the statistic

$p_v{/tex} represent the p valuePart aWe want to verify if the population proportion of young drivers, ages 18 – 24, having accidents is greater than 12%: Null hypothesis:[tex]p\leq 0.12$

Alternative hypothesis: $p > 0.12$

The statistic would be given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

Part b

For this case since we are conducting a right tailed test we need to find a critical value in the normal standard distribution who accumulates 0.05 of the area in the right and we got:

$z_{\alpha}=1.64$

Part c

For this case the statistic would be given by:

$z=\frac{0.134 -0.12}{\sqrt{\frac{0.12(1-0.12)}{1000}}}=1.362$

Part d

The p value can be calculated with the following probability:

$p_v =P(z>1.362)=0.0866$

Part e

For this case since the statistic is lower than the critical value and the p value higher than the significance level we have enough evidence to FAIL to reject the null hypothesis so then we don't have information to conclude that the true proportion is higher than 0.12

8 0

3 years ago

If (3, y) lies on the graph of y = -(2x), then y =<br> 1/8<br> -6<br> -8

Wittaler [7]

Answer:

The answer is -6.

Step-by-step explanation:

To find the value of y in (3, y), plug in 3 for x in y = -(2x) and solve for y.

y = -(2(3))

y = -6

y = -6, so the answer is -6.

7 0

3 years ago

Read 2 more answers

Find the difference between 1, 407 and 699

Rus_ich [418]

Answer:708

Step-by-step explanation:

7 0

3 years ago