A taxi travels 2 hours to make a 220 km trip. How fast does it travel?

The results of a mathematics placement exam at two different campuses of Mercy College follow: Campus Sample Size Sample Mean Po

Leona [35]

Answer:

$z=\frac{(33-31)-0}{\sqrt{\frac{8^2}{330}+\frac{7^2}{310}}}}=3.37$

$p_v =P(Z>3.37)=1-P(Z$

Comparing the p value with a significance level for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that the mean for the Campus 1 is significantly higher than the mean for the group 2.

Step-by-step explanation:

Data given

Campus Sample size Mean Population deviation

1 330 33 8

2 310 31 7

$\bar X_{1}=33$ represent the mean for sample 1

$\bar X_{2}=31$ represent the mean for sample 2

$\sigma_{1}=8$ represent the population standard deviation for 1

$\sigma_{2}=7$ represent the population standard deviation for 2

$n_{1}=330$ sample size for the group 1

$n_{2}=310$ sample size for the group 2

$\alpha$ Significance level provided

z would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the mean for Campus 1 is higher than the mean for Campus 2, the system of hypothesis would be:

Null hypothesis: $\mu_{1}-\mu_{2}\leq 0$

Alternative hypothesis: $\mu_{1} - \mu_{2}> 0$

We have the population standard deviation's, and the sample sizes are large enough we can apply a z test to compare means, and the statistic is given by:

$z=\frac{(\bar X_{1}-\bar X_{2})-\Delta}{\sqrt{\frac{\sigma^2_{1}}{n_{1}}+\frac{\sigma^2_{2}}{n_{2}}}}$ (1)

z-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.

With the info given we can replace in formula (1) like this:

$z=\frac{(33-31)-0}{\sqrt{\frac{8^2}{330}+\frac{7^2}{310}}}}=3.37$

P value

Since is a one right tailed test the p value would be:

$p_v =P(Z>3.37)=1-P(Z$

Comparing the p value with a significance level for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can say that the mean for the Campus 1 is significantly higher than the mean for the group 2.

5 0

2 years ago

last night, julie's pet hamster zoe kept julie awake for at least an hour running on her exercise wheel and scratching at the co

borishaifa [10]

Answer: $x+y\geq 1$ , $x>\frac{1}{4}$ , $x\geq 2y$ and $y\geq 0$

Step-by-step explanation:

Here, x represents the number of hours Zoe spent running on her wheel and y represents the number of hours spent scratching her cage.

Julie was awoke for at least an hour running on her exercise wheel and scratching the of her cage.

⇒ $x+y\geq 1$

She ran on her wheel at least twice as long as she scratched at the corners of her cage.

⇒ $x\geq 2y$

Also, She spent more than 1/4 hour running on her wheel.

⇒ $x>\frac{1}{4}$

And, we know that number of hours can not be negative.

⇒ $y\geq 0$

Therefore, the complete system of inequality which shows the given situation is,

$x+y\geq 1$ , $x>\frac{1}{4}$ and $x\geq 2y$ , $y\geq 0$

Note: the feasible region ( covered by the given system) is shown in the below graph.

6 0

2 years ago

If cyanide in a stream next to a gold mine increases from 240 ppm to 360 ppm, what percent increase is this?

avanturin [10]

Given :

Initial concentration , 240 ppm .

Final concentration , 360 ppm .

To Find :

Percent increase.

Solution :

Percentage increase is given by :

$=\dfrac{Final-Initial}{Initial}\times 100\\\\=\dfrac{360-240}{240}\times 100\\\\=50\%$

Therefore , percent increase is 50 % .

Hence , this is the required solution .

4 0

2 years ago

Which shows how to solve the equation Three-fourths x = negative 6 for x in one step?

My name is Ann [436]

option A i.e. Three-fourths (four-thirds) x = negative 6 (four-thirds).

Step-by-step explanation:

We have , The given expression as Three-fourths x = negative 6 , which can be written as $\frac{3}{4} (x) = -6$ . Now in order to solve this equation in one step , we must notice that coefficient of x must be 1 but it's $\frac{3}{4}$ , Let's make coefficient of x as 1 by multiplying both side of equations by 4/3:

$\frac{3}{4} (x) = -6$

⇒ $\frac{3}{4} (x) = -6$

⇒ $\frac{3}{4}(\frac{4}{3} ) (x) = -6(\frac{4}{3} )$

⇒ $x = -6(\frac{4}{3} )$

⇒ $x = -2(4)$

⇒ $x = -8$

Therefore, x= -8 & correct option to solve the equation Three-fourths x = negative 6 for x in one step is option A i.e. Three-fourths (four-thirds) x = negative 6 (four-thirds).

7 0

2 years ago

Read 2 more answers

Which are the solutions of x2 = –5x + 8? StartFraction negative 5 minus StartRoot 57 EndRoot Over 2 EndFraction comma StartFract

serg [7]

Answer:

$x=\frac{-5-\sqrt{57} }{2}\ or\ x=\frac{-5+\sqrt{57} }{2}$

Step-by-step explanation:

Given:

The equation to solve is given as:

$x^2=-5x+8$

Rearrange the given equation in standard form $ax^2+bx +c =0$ , where, $a,\ b,\ and\ c$ are constants.

Therefore, we add $5x-8$ on both sides to get,

$x^2+5x-8=0$

Here, $a=1,b=5,c=-8$

The solution of the above equation is determined using the quadratic formula which is given as:

$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

Plug in $a=1,b=5,c=-8$ and solve for $x$ .

$x=\frac{-5\pm \sqrt{5^2-4(1)(-8)}}{2(1)}\\x=\frac{-5\pm \sqrt{25+32}}{2}\\x=\frac{-5\pm \sqrt{57}}{2}\\\\\\\therefore x=\frac{-5-\sqrt{57} }{2}\ or\ x=\frac{-5+\sqrt{57} }{2}$

Therefore, the solutions are:

$x=\frac{-5-\sqrt{57} }{2}\ or\ x=\frac{-5+\sqrt{57} }{2}$

4 0

2 years ago

Read 2 more answers

A taxi travels 2 hours to make a 220 km trip. How fast does it travel?​

A taxi travels 2 hours to make a 220 km trip. How fast does it travel?