Ask question

Ask question

All categories

Keith_Richards [23]

2 years ago

12

Mike walked 3 miles in 45 minutes. What was his rate in miles per hour? A 1/4 miles per hourB 2 1/4 miles per hour C 4 miles per

hour D 15 miles per hour

2 answers:

Lemur [1.5K]2 years ago

5 0

Answer:

4 miles per hour

Step-by-step explanation:

I took it on k-12

erastova [34]2 years ago

4 0

Answer:

4 miles per hour

Step-by-step explanation:

I took the test for k12

You might be interested in

A side of the triangle below has been extended to form an exterior angle of 129 find the value of X

yawa3891 [41]

Basically the line is 180° in total.
If one side is 129°
then the other side is 180 - 129
which means x = 51°

7 0

2 years ago

There are 4,000 books in the town's library. Of these 2,600 are fiction. Write a percent equation that you can use to find the p

defon

Answer:

x = (2600/4000) × 100%

x = 0.65 × 100%

x = 65%

Step-by-step explanation:

The percentage equation that can be used to find the percent of books that are fiction can only be found where the number of fiction books is known and the total number of books available is known as well.

Given;

Number of fiction books = 2,600

Number of books = 4,000

let the percent of books that are fiction be x

x = (2600/4000) × 100%

x = 0.65 × 100%

x = 65%

5 0

3 years ago

A sample of 41 observations is selected from one population with a population standard deviation of 3.4. The sample mean is 100.

Marizza181 [45]

Answer:

a) If we see the alternative hypothesis we see that we are conducting a bilateral test or two tail.

b) (-1.9886, 1.9886)

c) $t=\frac{(100 -98.4)-(0)}{\sqrt{\frac{3.4^2}{41}}+\frac{5.6^2}{45}}=1.617$

d) $p_v =2*P(t_{84}>1.617) =0.1096$

So with the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the mean of the group 1 is NOT significantly different than the mean for the group 2.

e) $p_v =2*P(t_{84}>1.617) =0.1096$

We can use the following excel code to calculate it: "=2*(1-T.DIST(1.617;84;TRUE))"

Step-by-step explanation:

The system of hypothesis on this case are:

Null hypothesis: $\mu_1 = \mu_2$

Alternative hypothesis: $\mu_1 \neq \mu_2$

Or equivalently:

Null hypothesis: $\mu_1 - \mu_2 = 0$

Alternative hypothesis: $\mu_1 -\mu_2\neq 0$

Our notation on this case :

$n_1 =41$ represent the sample size for group 1

$n_2 =45$ represent the sample size for group 2

$\bar X_1 =100$ represent the sample mean for the group 1

$\bar X_2 =98.4$ represent the sample mean for the group 2

$s_1=3.4$ represent the sample standard deviation for group 1

$s_2=5.6$ represent the sample standard deviation for group 2

Part a

If we see the alternative hypothesis we see that we are conducting a bilateral test or two tail.

Part b

On this case since the significance level is 0.05 and we are conducting a bilateral test we have two critical values, and we need on each tail of the distribution $\alpha/2 = 0.025$ of the area.

The distribution on this cas since we don't know the population deviation for both samples is the t distribution with $df=n_1+n_2 -2= 41+45-2=84$ degrees of freedom.

We can use the following excel codes in order to find the critical values:

"=T.INV(0.025,84)", "=T.INV(1-0.025,84)"

And we got: (-1.9886, 1.9886)

Part c

The statistic is given by this formula:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{\sqrt{\frac{s^2_1}{n_1}}+\frac{S^2_2}{n_2}}$

And now we can calculate the statistic:

$t=\frac{(100 -98.4)-(0)}{\sqrt{\frac{3.4^2}{41}}+\frac{5.6^2}{45}}=1.617$

The degrees of freedom are given by:

$df=41+45-2=84$

Part d

And now we can calculate the p value using the altenative hypothesis:

$p_v =2*P(t_{84}>1.617) =0.1096$

So with the p value obtained and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the mean of the group 1 is NOT significantly different than the mean for the group 2.

Part e

$p_v =2*P(t_{84}>1.617) =0.1096$

We can use the following excel code to calculate it: "=2*(1-T.DIST(1.617;84;TRUE))"

8 0

3 years ago

Ronald and time both did there laundry today. Ronald does laundry every 6 days Tim does laundry every 9 days. How many days will

Vsevolod [243]

Answer:

18 days

Step-by-step explanation:

4 0

3 years ago

A line's y-intercept is 2, and its slope is 10. What is its equation in slope-intercept form?

Nataliya [291]

Answer:

m = 10x + 2

Step-by-step explanation:

4 0

2 years ago