Which property of equality should be used to cancel the operation performed on the variable in the following equation?

The weight of 8 science books is 28 pounds. What is the weight of 11 science books?

n200080 [17]

First,divide 28 divided by 8 which is 3.5
then,multiply your answer (3.5) times the 11 books.

so 3.5 times 11 which equals 38.5

8 0

3 years ago

It takes 400 people to take care of one cow. Write and explain your answer for how many people it takes to take care of 50 cows

prohojiy [21]

For 1 cow, it takes 400 people to take Care of it. So for 50 cows, it would be 400x50. which is 20,000

7 0

3 years ago

What happens when you combine rational and irrational numb<br> ers via addition and multiplication

Wewaii [24]

Since irrational numbers go on forever, no matter how much you add or multiply rational numbers, irrational numbers remain irrational.

5 0

4 years ago

How can 65% be broken down with friendly percents to find 65% of a number?

bogdanovich [222]

I always find 10% of an amount , in your case I would then times the answer by 6. Half 10% and add them together- 10%=? 5%=? 60%=? 65%=?

6 0

4 years ago

Read 2 more answers

A random sample of 49 measurements from one population had a sample mean of 15, with sample standard deviation 5. An independent

kotykmax [81]

Answer:

Comparing the p value with the significance level $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the difference between the two groups is significantly different.

Step-by-step explanation:

$\bar X_{1}=15$ represent the mean for sample 1

$\bar X_{2}=18$ represent the mean for sample 2

$s_{1}=5$ represent the sample standard deviation for 1

$s_{f}=6$ represent the sample standard deviation for 2

$n_{1}=49$ sample size for the group 2

$n_{2}=64$ sample size for the group 2

$\alpha=0.01$ Significance level provided

t would represent the statistic (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to check if the difference in the population means, the system of hypothesis would be:

Null hypothesis: $\mu_{1}-\mu_{2}=0$

Alternative hypothesis: $\mu_{1} - \mu_{2}\neq 0$

We don't have the population standard deviation's, so for this case is better apply a t test to compare means, and the statistic is given by:

$t=\frac{(\bar X_{1}-\bar X_{2})-\Delta}{\sqrt{\frac{s^2_{1}}{n_{1}}+\frac{s^2_{2}}{n_{2}}}}$ (1)

And the degrees of freedom are given by $df=n_1 +n_2 -2=49+64-2=111$

t-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

With the info given we can replace in formula (1) like this:

$t=\frac{(15-18)-0}{\sqrt{\frac{5^2}{49}+\frac{6^2}{64}}}}=-2.897$

P value

Since is a bilateral test the p value would be:

$p_v =2*P(t_{111}$

Comparing the p value with the significance level $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the difference between the two groups is significantly different.

7 0

3 years ago