Which of the following is an equivalent expression to: -2(-5x

A medical researcher wondered if there is a significant difference between the mean birth weight of boy and girl babies. Random

Yuliya22 [10]

Answer:

b) independent samples t-test

$t=\frac{(5.92 -5.74)-(0)}{\sqrt{\frac{1.88^2}{5}}+\frac{1.81^2}{5}}=0.154$

$p_v =2*P(t_{8}>0.154) =0.881$

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 (boys) is NOT significantly different than the mean for the group 2 (Girls).

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 :

$n_1 =5$ represent the sample size for group 1

$n_2 =5$ represent the sample size for group 2

We can calculate the mean and deviation for eaach group with the following formulas:

$\bar X= \frac{\sum_{i=1}^n X_i}{n}$

$s = \sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

$\bar X_1 =5.92$ represent the sample mean for the group 1

$\bar X_2 =5.74$ represent the sample mean for the group 2

$s_1=1.88$ represent the sample standard deviation for group 1

$s_2=1.81$ represent the sample standard deviation for group 2

If we see the alternative hypothesis we see that we are conducting a bilateral test and with independnet samples t test.

b) independent samples t-test

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:

$t=\frac{(5.92 -5.74)-(0)}{\sqrt{\frac{1.88^2}{5}}+\frac{1.81^2}{5}}=0.154$

The degrees of freedom are given by:

$df=5+5-2=8$

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

$p_v =2*P(t_{8}>0.154) =0.881$

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 (boys) is NOT significantly different than the mean for the group 2 (Girls).

7 0

3 years ago

What is 1 1 /2 x / 4 1/4<br> A. 4 1/8<br> B. 4 3/4<br> C. 6 3 /8<br> D. 5 1/4

sweet-ann [11.9K]

Answer:

c

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

*see attached image*

Leni [432]

Answer:

Sin, Cos, Tan and others are used to calculate the ratios of the sides of a right angled triangle by taking a certain angle as the angle of reference.

On the other hand, Sin‐¹, Cos‐¹ and Tan-¹ are used to find the reference angle used to calculate the ratio of sides.

For this question,

we need to find which option should used to calculate the angle the slide makes with the vertical support.

So the option will have to be either A, C or E.

here, the base is 2.81m and hypotenuse is 3.64m.

we know, Cos = base / hypotenuse

So the angle is given by Cos-¹(2.81/3.64)

Option C

4 0

3 years ago

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Select from the drop-down menus to correctly complete the sentence.

wlad13 [49]

Answer:

for anyone in the future that needs this the answer is The rule (x,y) ----> (x+2, y-4) represents a translation 2 units RIGHT and 4 units DOWN

Step-by-step explanation:

4 0

3 years ago

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A total of $76,000 is to be invested, some in bonds and some in certificates of deposit (CDs). If the amount invested in bonds

Anestetic [448]

Answer:

The amount invested as certificates of deposit is $ 35,000 and The amount invested as bonds is $ 41,000

Step-by-step explanation:

Given as :

The total amount to be invested as bonds and certificates of deposit (CD) = $76,000

Let the amount invested as bonds = $ x + $6000

And The amount invested as CD = $ x

Now, According to question

The amount invested as CD + The amount invested as bonds = $ x + $ x + $6000

Or, $ x + $ x + $6000 = $76,000

Or, $ 2x = $76,000 - $6000

So, $ 2x = $70,000

∴ x = $\frac{70000}{2}$ = $ 35,000

And $ x + $6000 = $ 35,000 + $6000 = $ 41,000

Hence The amount invested as certificates of deposit is $ 35,000 and The amount invested as bonds is $ 41,000 Answer

4 0

3 years ago

Which of the following is an equivalent expression to: -2(-5x - 8)