Simplify the expression: 4(

Please help me :D I will give brainiest to whoever is correct. :D

Feliz [49]

I think that there is 47 chocolate chips in total

8 0

4 years ago

Find the discount rate when the original price is $103.00 and the amount of the discount is $30.90

Sati [7]

Its 30% because if you take 103 put it in the calculator and divide by 100 you get 1.03 and multiply that time 30 you get 30.9 thats how you find percent

6 0

4 years ago

What is u? -u+300=200

vodomira [7]

Answer:

100

Step-by-step explanation:

200-300= -100 But the negative of a negative is a positive so the answer is: 100.

4 0

3 years ago

Read 2 more answers

Two brands of AAA batteries are tested in order to compare their voltage. The data summary can be found below.

garik1379 [7]

Answer:

The 95% confidence interval would be given by $0.281 \leq \mu_1 -\mu_2 \leq 0.529$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X_1 =9.2$ represent the sample mean 1

$\bar X_2 =8.8$ represent the sample mean 2

n1=27 represent the sample 1 size

n2=30 represent the sample 2 size

$\sigma_1 =0.3$ population standard deviation for sample 1

$\sigma_2 =0.1$ population standard deviation for sample 2

$\mu_1 -\mu_2$ parameter of interest.

Solution to the problem

The confidence interval for the difference of means is given by the following formula:

$(\bar X_1 -\bar X_2) \pm z_{\alpha/2}\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$ (1)

The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =9.2-8.8=0.4$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that $t_{\alpha/2}=1.96$

Now we have everything in order to replace into formula (1):

$0.4-1.96\sqrt{\frac{0.3^2}{27}+\frac{0.1^2}{30}}=0.281$

$0.4+1.96\sqrt{\frac{6^2}{36}+\frac{7^}{49}}=0.519$

So on this case the 95% confidence interval would be given by $0.281 \leq \mu_1 -\mu_2 \leq 0.529$

6 0

4 years ago

3. In the fig. AD = DC and AB = BC. Prove that ΔADB = ΔCDB<br>

xxMikexx [17]

Answer:

The two column proof is presented as follows;

The given parameters are;

$\overline {AD}$ = $\overline {DC}$ and $\overline {AB}$ = $\overline {BC}$

Statement ${}$ Reason

$\overline {AD}$ = $\overline {DC}$ and $\overline {AB}$ = $\overline {BC}$ ${}$ Given

$\overline {BD}$ ≅ $\overline {BD}$ ${}$ Reflexive property

$\overline {BD}$ = $\overline {BD}$ ${}$ By the definition of congruency

ΔADB ≅ ΔCDB ${}$ By Side-Side-Side (SSS) rule of congruency

ΔADB = ΔCDB ${}$ By the definition of congruency

If the three sides of one triangle are congruent to the corresponding three sides of another triangle, then both triangles are said to be congruent according to the SSS rule of congruency

Step-by-step explanation:

7 0

3 years ago

Simplify the expression: 4(–1 − 6n)