Evaluate x – 3y if x = –4 and y = –6. 22 14 –14

What is 4.5 X 0.75 please include answer with explanation also, any profile that sends jokes or any false information with jokes

butalik [34]

Answer:

3.375

Step-by-step explanation:

8 0

2 years ago

Seven divided by three fourths

grandymaker [24]

7/ (3/4)
= 7* (4/3)
= 28/3
= 9 1/3

The final answer is 9 1/3~

5 0

3 years ago

In a study to compare two different corrosion inhibitors, specimens of stainless steel were immersed for four hours in a solutio

liraira [26]

Answer:

$(242-220) -1.988 \sqrt{\frac{20^2}{47} +\frac{31^2}{42}} = 10.862$

$(242-220) +1.988 \sqrt{\frac{20^2}{47} +\frac{31^2}{42}} = 33.138$

And the confidence interval for the difference of means is given by:

$10.862 \leq \mu_A -\mu_B \leq 33.138$

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".

Data given and notation

$\bar X_{A}=242$ represent the mean for the sample A

$\bar X_{B}=220$ represent the mean for the sample B

$s_{A}=20$ represent the sample standard deviation for the sample A

$s_{B}=31$ represent the sample standard deviation for the sample B

$n_{A}=47$ sample size selected A

$n_{B}=42$ sample size selected B

$\alpha=0.05$ represent the significance level

Confidence =0.95 or 95%

Solution to the problem

For this case the confidence interval for the difference of means $\mu_A -\mu_B$ is given by:

$(\bar X_A -\bar X_B) \pm t_{\alpha/2} \sqrt{\frac{s^2_{A}}{n_{A}}+\frac{s^2_{B}}{n_{B}}}$

The degrees of freedom are given by:

$df = n_A +n_B -2= 47+42-2=87$

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: "=-T.INV(0.025,87)".And we see that $t_{\alpha/2}=1.988$

And the confidence interval would be given by

$(242-220) -1.988 \sqrt{\frac{20^2}{47} +\frac{31^2}{42}} = 10.862$

$(242-220) +1.988 \sqrt{\frac{20^2}{47} +\frac{31^2}{42}} = 33.138$

And the confidence interval for the difference of means is given by:

$10.862 \leq \mu_A -\mu_B \leq 33.138$

5 0

3 years ago

Marta has 8 yellow ribbons what are 2 different ways she can place the ribbons on her door or wall write two different addition

Drupady [299]

One way she can place the ribbons is to place them in groups of 8/2=4, making 4+4=8 ribbons (2 groups because 8/4=2). Next, she can put them in groups of 2 (we can make it out of only 2 if we want since 2 is a factor) to get 8/2=4 groups of 2 and 2+2+2+2=8

7 0

3 years ago

Please Help ASAP! Urgent! Will give Brainliest!

IRISSAK [1]

Answer:

D

Step-by-step explanation:

f(n − 1) + 10

f= (4-1) = 3

3+10= 13

6 0

3 years ago

Evaluate x – 3y if x = –4 and y = –6. 22 14 –14 –22