- 3/4 (x + 2) = 6<br> the / is a fraction can someone help

5) In a certain supermarket, a sample of 60 customers who used a self-service checkout lane averaged 5.2 minutes of checkout tim

Ne4ueva [31]

Answer:

$\S^2_p =\frac{(60-1)(3.1)^2 +(72 -1)(2.8)^2}{60 +72 -2}=8.643$

$S_p=2.940$

$t=\frac{(5.2 -6.1)-(0)}{2.940\sqrt{\frac{1}{60}+\frac{1}{72}}}=-1.751$

$df=60+72-2=130$

$p_v =P(t_{130}$

Assuming a significance level of $\alpha=0.05$ we have that the p value is lower than this significance level so then we can conclude that the mean for checkout time is significantly less for people who use the self-service lane

Step-by-step explanation:

Data given

Our notation on this case :

$n_1 =60$ represent the sample size for people who used a self service

$n_2 =72$ represent the sample size for people who used a cashier

$\bar X_1 =5.2$ represent the sample mean for people who used a self service

$\bar X_2 =6.1$ represent the sample mean people who used a cashier

$s_1=3.1$ represent the sample standard deviation for people who used a self service

$s_2=2.8$ represent the sample standard deviation for people who used a cashier

Assumptions

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

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

The statistic is given by:

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

And 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:

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

System of hypothesis

Null hypothesis: $\mu_1 \geq \mu_2$

Alternative hypothesis: $\mu_1 < \mu_2$

This system is equivalent to:

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

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

We can find the pooled variance:

$\S^2_p =\frac{(60-1)(3.1)^2 +(72 -1)(2.8)^2}{60 +72 -2}=8.643$

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

$S_p=2.940$

The statistic is given by:

$t=\frac{(5.2 -6.1)-(0)}{2.940\sqrt{\frac{1}{60}+\frac{1}{72}}}=-1.751$

The degrees of freedom are given by:

$df=60+72-2=130$

And now we can calculate the p value with:

$p_v =P(t_{130}$

Assuming a significance level of $\alpha=0.05$ we have that the p value is lower than this significance level so then we can conclude that the mean for checkout time is significantly less for people who use the self-service lane

5 0

3 years ago

A bug starts at the origin of the coordinate plane. The bug moves 1/4 units right and 1/4 units down to point A. Which graph sho

Vsevolod [243]

Answer:

<h2>The Answer would be (0.25, -0.25)</h2>

Step-by-step explanation:

Since you started at the origin of the plane, it would be obvious that your place would be 0.25 on the x-axis. The template for this would be (x,y) x- right and left. y- up and down. On the y-axis, the bug moved 0.25 DOWN to point A. That would be a negative since on the y-axis, it counts up to positives and down to negative. Similar to the x-axis, it counts right to positives, left to negatives. Hope this helped!

3 0

3 years ago

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What is the sum of the measures of the exterior angles in a nonagon? explain

DedPeter [7]

The sum of the measures of all exterior angle in a polygon with n sides is always $360^{\circ}$ .

Nonagon is a polygon with 9 sides. If this nonagon is regular or equiangular, then all interior angle are congruent, and therefore all exterior angles are congruent. Then the measure of each exterior angle is $\dfrac{360^{\circ}}{9} =40^{\circ}$ .

5 0

3 years ago

Does y=2x+3 represents a Linear relationship

Flauer [41]

Answer:

Yes

Step-by-step explanation:

Just trust me it does

7 0

3 years ago

Suppose P varies directly with q and that P=36 when q=9 . <br> What is the value of P when q=3?

Yuri [45]

Answer:

P=12

Step-by-step explanation:

Since P=36 and q=9, this looks like a ratio of 4:1. So if q=3, multiply that value by 4 to get your answer

7 0

3 years ago

- 3/4 (x + 2) = 6 the / is a fraction can someone help