I NEED HELP PLEASE, THANKS!

I NEED HELP!!! 21-22

Nesterboy [21]

21. P=118

21. Q=142

22. P=120

22. R=60

22. S=60

3 0

3 years ago

High population density can cause increases in competition for resources, such as food and shelter. The table shows the number o

Taya2010 [7]

Answer:

C

Step-by-step explanation:

Ed 2021

4 0

3 years ago

Read 2 more answers

Based on an indication that mean daily car rental rates may be higher for Boston than for Dallas, a survey of eight car rental c

Elina [12.6K]

Answer:

$t=\frac{(47 -44)-(0)}{3\sqrt{\frac{1}{8}+\frac{1}{9}}}=2.058$

The degrees of freedom are:

$df=8+9-2=15$

And the p value would be:

$p_v =P(t_{15}>2.058) =0.0287$

Since we have a p value lower than the significance level given of 0.05 we can reject the null hypothesis and we can conclude that the true mean for car rental rates in Boston are signiﬁcantly higher than those in Dallas

Step-by-step explanation:

Data given

$n_1 =8$ represent the sample size for group Boston

$n_2 =9$ represent the sample size for group Dallas

$\bar X_1 =47$ represent the sample mean for the group Boston

$\bar X_2 =44$ represent the sample mean for the group Dallas

$s_1=3$ represent the sample standard deviation for group Boston

$s_2=3$ represent the sample standard deviation for group Dallas

We can assume that we have independent samples from two normal distributions with equal variances and that is:

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

Let the subindex 1 for Boston and 2 for Dallas we want to check the following hypothesis:

Null hypothesis: $\mu_1 \leq \mu_2$

Alternative hypothesis: $\mu_1 > \mu_2$

The statistic is given by this formula:

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

Where t follows a t student distribution with $n_1+n_2 -2$ degrees of freedom and the pooled variance $S^2_p$ is given by this formula:

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

Replacing we got:

$\S^2_p =\frac{(8-1)(3)^2 +(9 -1)(3)^2}{8 +9 -2}=9$

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

$S_p=3$

The statitsic would be:

$t=\frac{(47 -44)-(0)}{3\sqrt{\frac{1}{8}+\frac{1}{9}}}=2.058$

The degrees of freedom are:

$df=8+9-2=15$

And the p value would be:

$p_v =P(t_{15}>2.058) =0.0287$

Since we have a p value lower than the significance level given of 0.05 we can reject the null hypothesis and we can conclude that the true mean for car rental rates in Boston are signiﬁcantly higher than those in Dallas

5 0

3 years ago

Marianne, Arlene, Tyler, and I worked together to complete a group project. Marianne completed 1/5 of the project. Arlene comple

Nookie1986 [14]

Marianne completed 2/10 and Arlene 3/10 so that’s 5/10 which means you and Tyler did 5/10 if you divide that by 2 it’s 5/20 I think but I don’t really understand as the possible answers aren’t fractions? Hopefully that’s right haha

3 0

3 years ago

Need help on hw

Katyanochek1 [597]

Answer:

Perry started with 40 stamps

Step-by-step explanation:

If perry is starting with 40 stamps and gets rid of half of them he will have 20 stamps + 20 stamps would be 40.

7 0

2 years ago