Find the instantaneous rate of change of f(x)= 4/x+3 at x=5

A county is considering rasing the speed limit on a road because they claim that the mean speed of vehicles is greater than 30 m

DochEvi [55]

Answer:

No, at alpha equals 0.10, we do not have enough evidence to support the county's claim.

Step-by-step explanation:

We are given that a county is considering raising the speed limit on a road because they claim that the mean speed of vehicles is greater than 30 miles per hour.

A random sample of 15 vehicles has a mean speed of 31 miles per hour and a standard deviation of 4.7 miles per hour.

Let $\mu$ = true mean speed of the vehicles.

SO, Null Hypothesis, $H_0$ : $\mu \leq$ 30 miles per hour {means that the mean speed of vehicles is lesser than or equal to 30 miles per hour}

Alternate Hypothesis, $H_A$ : $\mu$ > 30 miles per hour {means that the mean speed of vehicles is greater than 30 miles per hour}

The test statistics that will be used here is One-sample t test statistics as we don't know about the population standard deviation;

T.S. = $\frac{\bar X -\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean speed of 15 vehicles = 31 mph

s = sample standard deviation = 4.7 mph

n = sample of vehicles = 15

So, test statistics = $\frac{31-30}{\frac{4.7}{\sqrt{15} } }$ ~ $t_1_4$

= 0.824

Hence, the value of test statistics is 0.824.

Now at 0.10 significance level, the t table gives critical value of 1.345 at 14 degree of freedom for right-tailed test. Since our test statistics is less than the critical value of t as 0.824 < 1.345, so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region.

Therefore, we conclude that the mean speed of vehicles is lesser than or equal to 30 miles per hour which means that the county's claim is not supported.

4 0

4 years ago

Use the arc length formula to find the length of the curve y = 4x − 5, −1 ≤ x ≤ 2. check your answer by noting that the curve is

professor190 [17]

Ok, here we go. Pay attention. The formula for the arc length is $AL= \int\limits^b_a { \sqrt{1+( \frac{dy}{dx})^2 } } \, dx$ . That means that to use that formula we have to find the derivative of the function and square it. Our function is y = 4x-5, so y'=4. Our formula now, filled in accordingly, is $AL= \int\limits^2_1 { \sqrt{1+4^2} } \, dx$ (that 1 is supposed to be negative; not sure if it is til I post the final answer). After the simplification we have the integral from -1 to 2 of $\sqrt{17}$ . Integrating that we have $AL= \sqrt{17}x$ from -1 to 2. $2 \sqrt{17}-(-1 \sqrt{17} )$ gives us $3 \sqrt{17}$ . Now we need to do the distance formula with this. But we need 2 coordinates for that. Our bounds are x=-1 and x=2. We will fill those x values in to the function and solve for y. When x = -1, y=4(-1)-5 and y = -9. So the point is (-1, -9). Doing the same with x = 2, y=4(2)-5 and y = 3. So the point is (2, 3). Use those in the distance formula accordingly: $d= \sqrt{(2-(-1))^2+(3-(-9))^2}$ which simplifies to $d= \sqrt{9+144}= \sqrt{153}$ . The square root of 153 can be simplified into the square root of 9*17. Pulling out the perfect square of 9 as a 3 leaves us with $3 \sqrt{17}$ . And there you go!

5 0

3 years ago

The dot product of u with itself is 24. what is the magnitude of u? 2sqrt 3 2sqrt 6 12 24

My name is Ann [436]

Hat do you know someone called English

6 0

4 years ago

Round the greater number to the tens place. Then calculate the product.

Nonamiya [84]

Answer:

d:192

Step-by-step explanation:

6 0

3 years ago

Two cars traveled equal distances in different amounts of time. Car A traveled the distance in 2 h, and Car B traveled the dista

scZoUnD [109]

The answer to this question
is 60mph

3 0

3 years ago