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3 years ago

7

This bar graph shows the money earned from the sale of skateboards one Saturday at four stores. What can you tell from the infor

mation in this graph? A) Skateaway sold the most skateboards. B) Skating is more popular at Great Skates. At Ben's Boards, skateboards cost the least. D) Skateaway made the most money selling skateboards.

2 answers:

aev [14]3 years ago

8 0

Answer:

D) Skateaway made the most money selling skateboards.

I just took the test I got it right.

Stay gold

-BARSIC- [3]3 years ago

6 0

Answer:

its D <3

Step-by-step explanation:

hope this helps :)

You might be interested in

Rob peeled 125 oranges in 5 hours. At that rate, how many oranges<br> would he peel in 12 minutes?

marin [14]

Answer:

$\boxed {\tt 5 \ oranges}$

Step-by-step explanation:

Let's set up a proportion.

$\frac{oranges}{minutes} =\frac{oranges}{minutes}$

He can peel 125 oranges in 5 hours. First, let's find the minutes in 5 hours.

There are 60 minutes in 1 hour, so multiply 60 and 5 (60*5=300). There are 300 minutes in 5 hours.

$\frac{125 \ oranges}{300 \ minutes}=\frac{oranges}{minutes}$

We don't know how many oranges he can peel in 12 minutes. So we say he can peel x oranges in 12 minutes.

$\frac{125 \ oranges}{300 \ minutes}=\frac{x \ oranges}{12 \ minutes}$

$\frac{125 \ }{300 \ }=\frac{x \ }{12 }$

Solve for x by isolating it. x is being divided by 12. The inverse of division is multiplication. Multiply both sides of the proportion by 12.

$12*\frac{125 \ }{300 \ }=\frac{x \ }{12 \ }*12$

$12*\frac{125 \ }{300 \ }=x$

$12*0.416666667=x$

$5=x$

Rob can peel 5 oranges in 12 minutes.

6 0

3 years ago

Read 2 more answers

What is the product of 3x1/5?

vagabundo [1.1K]

Answer: 3/5

Step-by-step explanation: 1/5*3=1/5+1/5+1/5=3/5

7 0

3 years ago

Two catalysts may be used in a batch chemical process. Twelve batches were prepared using catalyst 1, resulting in an average yi

aalyn [17]

Answer:

a) $t=\frac{(91-85)-(0)}{2.490\sqrt{\frac{1}{12}}+\frac{1}{15}}=6.222$

$df=12+15-2=25$

$p_v =P(t_{25}>6.222) =8.26x10^{-7}$

So with the p value obtained and using the significance level given $\alpha=0.01$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis.

b) $(91-85) -2.79 *2.490 \sqrt{\frac{1}{12} +\frac{1}{15}} =3.309$

$(91-85) +2.79 *2.490 \sqrt{\frac{1}{12} +\frac{1}{15}} =8.691$

Step-by-step explanation:

Notation and hypothesis

When we have two independent samples from two normal distributions with equal variances we are assuming that

$\sigma^2_1 =\sigma^2_2 =\sigma^2$

And the statistic is given by this formula:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{S_p\sqrt{\frac{1}{n_1}}+\frac{1}{n_2}}$

Where t follows a t distribution with $n_1+n_2 -2$ degrees of freedom and the pooled variance $S^2_p$ is given by this formula:

$\S^2_p =\frac{(n_1-1)S^2_1 +(n_2 -1)S^2_2}{n_1 +n_2 -2}$

This last one is an unbiased estimator of the common variance $\sigma^2$

Part a

The system of hypothesis on this case are:

Null hypothesis: $\mu_2 \leq \mu_1$

Alternative hypothesis: $\mu_2 > \mu_1$

Or equivalently:

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

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

Our notation on this case :

$n_1 =12$ represent the sample size for group 1

$n_2 =15$ represent the sample size for group 2

$\bar X_1 =85$ represent the sample mean for the group 1

$\bar X_2 =91$ represent the sample mean for the group 2

$s_1=3$ represent the sample standard deviation for group 1

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

First we can begin finding the pooled variance:

$\S^2_p =\frac{(12-1)(3)^2 +(15 -1)(2)^2}{12 +15 -2}=6.2$

And the deviation would be just the square root of the variance:

$S_p=2.490$

Calculate the statistic

And now we can calculate the statistic:

$t=\frac{(91-85)-(0)}{2.490\sqrt{\frac{1}{12}}+\frac{1}{15}}=6.222$

Now we can calculate the degrees of freedom given by:

$df=12+15-2=25$

Calculate the p value

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

$p_v =P(t_{25}>6.222) =8.26x10^{-7}$

Conclusion

So with the p value obtained and using the significance level given $\alpha=0.01$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis.

Part b

For this case the confidence interval is given by:

$(\bar X_1 -\bar X_2) \pm t_{\alpha/2} S_p \sqrt{\frac{1}{n_1} +\frac{1}{n_2}}$

For the 99% of confidence we have $\alpha=1-0.99 = 0.01$ and $\alpha/2 =0.005$ and the critical value with 25 degrees of freedom on the t distribution is $t_{\alpha/2}= 2.79$

And replacing we got:

$(91-85) -2.79 *2.490 \sqrt{\frac{1}{12} +\frac{1}{15}} =3.309$

$(91-85) +2.79 *2.490 \sqrt{\frac{1}{12} +\frac{1}{15}} =8.691$

7 0

3 years ago

Can you please help me please =( I beg you

emmasim [6.3K]

Answer:

I think he made a mastake a step 3

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

Katoni bought 2 1/2 dozen pencils . There are 12 pencils in a dozen. How many pencils did Katoni buy?

sergeinik [125]

Half of a dozen is 6. And 12+12 is 24 and 24+6 is 30. So Katoni bought 30 pencils.

5 0

2 years ago