What’s 1+1 ? A: 2 B: 69 C: 420 D: 3

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

4 years ago

When a bush was first planted in a garden, it was 12 cm tall. After two weeks, it was 120% as tall as when it was first planted.

Lubov Fominskaja [6]

Answer:

26.4

Step-by-step explanation:

12 times 120% + 12

8 0

3 years ago

Read 2 more answers

Read the questions below (best gets 30 points)

myrzilka [38]

Answer:

2 is 67

3 is 45

4 is 71

6 is x(all angles)

7 is 28

8 is 33

3 0

4 years ago

) A random sample of n measurements was selected from a population with unknown mean μ and standard deviation σ. Calculate a 95%

UNO [17]

Answer:

ask MisterBrainly for help

4 0

3 years ago

Solve each given equation and show your work. Tell whether each equation has one solution, an infinite number of solutions, or n

cluponka [151]

(a) 2x+4(x-1)=2

2x+4x-4=2---- Distrubution of 4(x-1)

6x-4=2---- Combining like terms

6x=6---- Making -4 equal 0 by adding +4 to both sides

x=1---- Divide the coefficiant (6)

(b) 25-x=15-(3x+10)

25-x=15-3x-10----Distribute the -1

25-x=5-3x---- Combine like terms

25=5-2x---- Make -x equal 0 by adding +x to both sides

20=-2x---- Make 5 equal zero by subtracting 5 (or adding -5) to both sides

-10=x---- Divide by the coefficiant (-2)

(c) 4x= 2x+2x+5(x-x)

4x=2x+2x+5(0)---- Distribute. Alright this might look hard but realy it is 1x-1x so the answer is 0

4x=2x+2x---- 5 times 0 is 0

4x=4x---- Combine like terms

x=x ---- divide by the coefficiant

3 0

3 years ago