Ask question

Ask question

All categories

Vladimir79 [104]

3 years ago

14

A truck driver who covers the interstate in 4 1/2hours traveling at the posted speed of 55 mph. If the speed limit is raised to

65 mph, how much time will the same trip require

1 answer:

kotegsom [21]3 years ago

6 0

Answer: The same trip will require 3.8 hours.

Step-by-step explanation:

Since we have given that

Time = $4\dfrac{1}{2}=\dfrac{9}{2}$

Speed = 55 mph

So, distance would be

$Speed\times time=55\times 4.5=247.5\ miles$

If the speed limit = 65 mph

So, time will be

$\dfrac{247.5}{65}=3.8\ hours$

Hence, the same trip will require 3.8 hours.

You might be interested in

Working alone, Ryan can dig a 10 ft by 10 ft hole in 5 hours Castel can dig the same hole in 6 hours how long would it take them

Fed [463]

Answer:

The time taken by both boys to complete work = 2.73 hours

Step-by-step explanation:

Time taken by rayan to dig hole $T_{1}$ = 5 hours

Time taken by castel to dig hole $T_{2}$ = 6 hours

Now the time taken by both persons working together

$T = \frac{T_{1} T_{2} }{T_{1} + T_{2}}$

Put all the values in above formula we get

$T = \frac{ 30 }{6 + 5}$

$T = \frac{30}{11}$

T = 2.73 hours

Therefore the time taken by both boys to complete work = 2.73 hours

6 0

3 years ago

The data shown on the scatter plot below demonstrates the relationship between the time of day and the total number

viva [34]

Answer:

Good question! The correct answer is a) increases and b) increases.

While the pair of answers a) decreases and b) decreases or the pair a) stays the same and b) stays the same would be technically correct answers, this is the best way of describing the trend of the scatter plot; typically, trends are described by how the dependent or y-variable responds to the independent or x-variable increasing.

6 0

3 years ago

The two objects are the same height, and the cylinder is just wide enough for the the box to fit inside with all 4 vertical edge

OLEGan [10]

Answer:

The answer is below

Step-by-step explanation:

The volume of a box with a length of l, width of w and a height of h is given by the formula:

volume of the box = length * width * height = lwh

The volume of a cylinder with a height of h, and radius r is given by the formula:

volume of the cylinder = π * radius² * height = πr²h

Since the box and the cylinder have the same height and the cylinder is wide enough for the box to be placed inside, this means that the box has a volume greater than that of the cylinder. Hence:

If the box can take 8 cups, the cylinder would be able to take 10 cups.

7 0

2 years ago

Dual-energy X-ray absorptiometry (DXA) is a technique for measuring bone health. One of the most common measures is total body b

sesenic [268]

Answer:

$\bar d=\frac{\sum_{i=1}^n d_i}{n}=-0.001$

$s=\sqrt{\frac{\sum_{i=1}^n (x_i -\bar X)^2}{n-1}}=0.0095$

-The sample is too small to make judgments about skewness or symmetry.

H0: $\mu_{1}=\mu_{2}$

H1: $\mu_{1} \neq \mu_{2}$

$t=\frac{1.173-1.174}{\sqrt{\frac{0.1506^2}{8}+\frac{0.1495^2}{8}}}=-0.013$

$p_v =2*P(t_{(14)}$

So the p value is a very high value and using any significance level for example $\alpha=0.05, 0,1,0.15$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and a we don't have a significant difference between the two means.

Step-by-step explanation:

First we need to find the difference defined as:

(Operator 1 minus Operator 2)

d1=1.326-1.323=0.003 d2=1.337-1.322=0.015

d3=1.079-1.073=0.006 d4=1.229-1.233=-0.004

d5=0.936-0.934=0.002 d6=1.009-1.019=-0.01

d7=1.179-1.184=-0.005 d8=1.289-1.304=-0.015

Now we can calculate the mean of differences given by:

$\bar d=\frac{\sum_{i=1}^n d_i}{n}=-0.001$

And for the sample deviation we can use the following formula:

$s=\sqrt{\frac{\sum_{i=1}^n (x_i -\bar X)^2}{n-1}}=0.0095$

Describe the distribution of these differences using words. (which one is correct)

We can plot the distribution of the differences with the folowing code in R

differences<-c(0.003,0.015,0.006,-0.004,0.002,-0.01,-0.005,-0.015)

hist(differences)

And we got the image attached. And we can see that the distribution is right skewed but we don't have anough info to provide a conclusion with just 8 differnences.

-The sample is too small to make judgments about skewness or symmetry.

Use a significance test to examine the null hypothesis that the two operators have the same mean. Give the test statistic. (Round your answer to three decimal places.)

$\bar X_{1}=1.173$ represent the mean for the operator 1

$\bar X_{2}=1.174$ represent the mean for the operator 2

$s_{1}=0.1506$ represent the sample standard deviation for the operator 1

$s_{2}=0.1495$ represent the sample standard deviation for the operator 2

$n_{1}=8$ sample size for the operator 1

$n_{2}=8$ sample size for the operator 2

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the means for the two groups are the same, the system of hypothesis would be:

H0: $\mu_{1}=\mu_{2}$

H1: $\mu_{1} \neq \mu_{2}$

If we analyze the size for the samples both are less than 30 so for this case is better apply a t test to compare means, and the statistic is given by:

$t=\frac{\bar X_{1}-\bar X_{2}}{\sqrt{\frac{s^2_{1}}{n_{1}}+\frac{s^2_{2}}{n_{2}}}}$ (1)

t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

Calculate the statistic

We can replace in formula (1) like this:

$t=\frac{1.173-1.174}{\sqrt{\frac{0.1506^2}{8}+\frac{0.1495^2}{8}}}=-0.013$

Statistical decision

For this case we don't have a significance level provided $\alpha$ , but we can calculate the p value for this test. The first step is calculate the degrees of freedom, on this case:

$df=n_{1}+n_{2}-2=8+8-2=14$

Since is a bilateral test the p value would be:

$p_v =2*P(t_{(14)}$

So the p value is a very high value and using any significance level for example $\alpha=0.05, 0,1,0.15$ always $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and a we don't have a significant difference between the two means.

8 0

3 years ago

I did my best to fit it all lol, can someone please help? <3

pav-90 [236]

Answer:

8a. 0 8b. -1/3

Step-by-step explanation:

slope formula: $\frac{y_{2} - y_{1}}{x_{2} - x{1}}$

8a. => (8 + 12)/(17 - 17) = 20/0 = 0

8b. (1 + 2)/(-3 - 6) = 3/-9 = - 1/3

3 0

3 years ago

Read 2 more answers