Please help i am really struggling

Two trains, Train A and Train B, weigh a total of 300 tons. Train A is heavier than Train B. The difference of their weights i

eduard

Answer:

Train A = 214

Train B = 86

Step-by-step explanation:

a + b = 300

a - b = 128

a + b = 300

a = 128 + b

(128 + b) + b = 300

128 + b + b = 300

128 + 2b = 300

2b = 300 - 128

2b = 172

b = 172 ÷ 2

b = 86

a = 128 + b

a = 128 + (86)

a = 214

7 0

3 years ago

A recent health report revealed that a woman with insurance spends an average of 2.3 days in the hospital following a routine ch

cupoosta [38]

Answer:

$t=\frac{2.3-1.9}{\sqrt{\frac{0.6^2}{16}+\frac{0.3^2}{16}}}}=2.385$

$p_v =2*P(t_{30}>2.385)=0.0236$

Comparing the p value with the significance level given $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we FAIL to reject the null hypothesis

The confidence interval would be given by:

$(2.3 -1.9) - 2.75*\sqrt{\frac{0.6^2}{16}+\frac{0.3^2}{16}}}=-0.0611$

$(2.3 -1.9) + 2.75* \sqrt{\frac{0.6^2}{16}+\frac{0.3^2}{16}}}=0.861$

Step-by-step explanation:

Data given and notation

$\bar X_{insurance}=2.3$ represent the mean for insurance

$\bar X_{No. ins}=1.9$ represent the mean withour insurance

$s_{Insurance}=0.6$ represent the sample standard deviation for the insurance case

$s_{No. Ins}=0.3$ represent the sample standard deviation for the No insurance case

$n_{Insurance}=16$ sample size for insurance

$n_{No. Iss}=16$ sample size for no insurance

t would represent the statistic (variable of interest)

$\alpha=0.01$ significance level provided

Develop the null and alternative hypotheses for this study?

We need to conduct a hypothesis in order to check if the means for the two groups are different, the system of hypothesis would be:

Null hypothesis: $\mu_{Insu}=\mu_{No. Ins}$

Alternative hypothesis: $\mu_{Ins} \neq \mu_{No. Ins}$

Since we know the population deviations for each group, for this case is better apply a z test to compare means, and the statistic is given by:

$t=\frac{\bar X_{Ins}-\bar X_{No.Ins}}{\sqrt{\frac{s^2_{Ins}}{n_{Ins}}+\frac{s^2_{No. Ins}}{n_{No. Ins}}}}$ (1)

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.

Calculate the value of the test statistic for this hypothesis testing.

Since we have all the values we can replace in formula (1) like this:

$t=\frac{2.3-1.9}{\sqrt{\frac{0.6^2}{16}+\frac{0.3^2}{16}}}}=2.385$

What is the p-value for this hypothesis test?

The degrees of freedom are given by:

$df = n_{ins} +n_{No Ins}-2=16+16-2 =30$

Since is a bilateral test the p value would be:

$p_v =2*P(t_{30}>2.385)=0.0236$

Based on the p-value, what is your conclusion?

Comparing the p value with the significance level given $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we FAIL to reject the null hypothesis

The confidence interval would be given by:

$(2.3 -1.9) - 2.75*\sqrt{\frac{0.6^2}{16}+\frac{0.3^2}{16}}}=-0.0611$

$(2.3 -1.9) + 2.75* \sqrt{\frac{0.6^2}{16}+\frac{0.3^2}{16}}}=0.861$

6 0

3 years ago

A researcher planning a survey of heads of households in New York has census lists for each of the 62 counties in the state. The

wel

Answer: A. It is more susceptible to bias than would be a simple random sample.

hope this helps

3 0

3 years ago

The seventh grade students are having an end-of-year party in the school cafeteria. There are 754 students attending the party.

Leno4ka [110]

Answer:

Determine the number of tables by dividing 754 by 6. If there is a remainder, the answer will need to be rounded tenths or hundredths . There is a remainder, so 125.6 tables are needed.

Step-by-step explanation:

8 0

2 years ago

The volume V of a cylinder is computed using the values 8.8m for the diameter and 5.8m for the height. Use the linear approximat

Delvig [45]

Answer:

The maximum error is approximately Ev=24%

Step-by-step explanation:

the volume of the cylinder V is

V= π/4*H*D²

where H= height and D= diameter

the variation of V will be

dV = (∂V/∂H)*dH + (∂V/∂D)*dD

dV = π/4*D²*dH +π/2*H*D*dD

if we divide by the volume V

dV /V = (π/4*D²*dH +π/2*H*D*dD )/( π/4*H*D²) = dH/H + 2*dD/D

dV /V = dH/H + 2*dD/D

then we can approximate

error in V= Ev= ΔV/V ≈ dV/V

error in H= Eh=ΔH/H ≈ dH/H

error in D= Ed=ΔD/D ≈ dD/D

thus

Ev= Eh + 2*Ed

since Ed=Eh=E=8%

Ev= Eh + 2*Ed =3*E=3*8%=24%

Ev= 24%

therefore the maximum error is approximately Ev=24%

5 0

3 years ago