Ques

A copy machine makes 119 copies in 4 minutes and 15 seconds. how many copies does it make per minute?

FrozenT [24]

The answer is roughly 21.4 copies per minute
an estimate

4 0

3 years ago

Which number is not a perfect square?<br> A. 4<br> B. 9<br> C. 111<br> D. 81

Paladinen [302]

Answer:

C 111

Step-by-step explanation:

7 0

2 years ago

Read 2 more answers

Can you help me solve for x?

sergiy2304 [10]

Answer:

x = 12

Step-by-step explanation:

The exterior angle of a triangle is equal to the sum of the opposite interior angles

10x-10 = 60 +4x+2

Combine like terms

10x-10 = 62+4x

Subtract 4x from each side

10x-4x -10 = 62 +4x-4x

6x -10 = 62

Add 10 to each side

6x-10+10 = 62+10

6x= 72

Divide by 6

6x/6 = 72/6

x = 12

3 0

3 years ago

This month Salesperson A made 11% of $67,530. Salesperson B made 8% of $85,740. Who made more commission this month? How much di

laiz [17]

Answer:

Salesman A made $569.1 more commission than salesman B

Step-by-step explanation:

(11/100)*67530= (amount made by salesperson A)

=7428.3

(8/100)*85740= (amount made by salesperson B)

=6859.2

A-B= 569.1

Hope this helps :D

6 0

3 years ago

An auto company claims that the fuel efficiency of its sedan has been substantially improved. A consumer advocate organization w

zzz [600]

Answer:

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=\frac{0.983 -0}{\frac{1.685}{\sqrt{12}}}=2.021$

$df=n-1=12-1=11$

$p_v =P(t_{(11)}>2.021) =0.0342$

If we compare the the p value with the significance level provided $\alpha=0.1$ , we see that $p_v < \alpha$ , so then we can reject the null hypothesis. and there is a significant increase in the miles per gallon from 2017 to 2019 at 10% of significance.

Step-by-step explanation:

Previous concepts

A paired t-test is used to compare two population means where you have two samples in which observations in one sample can be paired with observations in the other sample. For example if we have Before-and-after observations (This problem) we can use it.

Let put some notation :

x=test value 2017 , y = test value 2019

x: 28.7 32.1 29.6 30.5 31.9 30.9 32.3 33.1 29.6 30.8 31.1 31.6

y: 31.1 32.4 31.3 33.5 31.7 32.0 31.8 29.9 31.0 32.8 32.7 33.8

Solution to the problem

The system of hypothesis for this case are:

Null hypothesis: $\mu_y- \mu_x \leq 0$

Alternative hypothesis: $\mu_y -\mu_x >0$

Because if we have an improvement we expect that the values for 2019 would be higher compared with the values for 2017

The first step is calculate the difference $d_i=y_i-x_i$ and we obtain this:

d: 2.4, 0.3, 1.7,3,-0.2, 1.1, -0.5, -3.2, 1.4, 2, 1.6, 2.2

The second step is calculate the mean difference

$\bar d= \frac{\sum_{i=1}^n d_i}{n}= \frac{11.8}{12}=0.983$

The third step would be calculate the standard deviation for the differences, and we got:

$s_d =\frac{\sum_{i=1}^n (d_i -\bar d)^2}{n-1} =1.685$

We assume that the true difference follows a normal distribution. The 4th step is calculate the statistic given by :

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=\frac{0.983 -0}{\frac{1.685}{\sqrt{12}}}=2.021$

The next step is calculate the degrees of freedom given by:

$df=n-1=12-1=11$

Now we can calculate the p value, since we have a right tailed test the p value is given by:

$p_v =P(t_{(11)}>2.021) =0.0342$

If we compare the the p value with the significance level provided $\alpha=0.1$ , we see that $p_v < \alpha$ , so then we can reject the null hypothesis. and there is a significant increase in the miles per gallon from 2017 to 2019 at 10% of significance.

4 0

3 years ago