Question

In: Statistics and Probability

The hydrocarbon emissions at idling speed in parts per million (ppm) for automobiles of 1980 and...

  1. The hydrocarbon emissions at idling speed in parts per million (ppm) for automobiles of 1980 and 1990 model years are given for 20 randomly and independently selected cars. The data can be found in the excel file Auto with variables name Model and Emission. At the 5% significance level, do we have sufficient evidence to conclude that the true mean hydrocarbon emissions were greater for 1980 models than 1990 models? (17 points total)

  1. Label the Parameters: (3 points)
  2. State null and alternative hypotheses in parameter notation: (2 points)

H0:

Ha:  

  1. Propose an appropriate hypothesis test. Explain! (2 points)           
  2. Verify the required conditions for the proposed hypothesis test: (3 points)
Randomization assumption: 

Normality assumption: 

Equal population variance assumption: 

Note: Attach R codes and outputs in the following space:
  1. Report a test statistic, df, and p-value. (3 points)

Test statistic =

df =

p-value =

Note: Attach R codes and outputs in the following space:
  1. Make a decision of hypothesis test: (2 points)
  2. Make a conclusion of hypothesis test in context: (2 points)
    Model Emission
    Eighty 380
    Eighty 475
    Eighty 241
    Eighty 340
    Eighty 435
    Eighty 210
    Eighty 300
    Eighty 306
    Eighty 210
    Eighty 450
    Eighty 241
    Eighty 590
    Eighty 542
    Eighty 440
    Eighty 225
    Eighty 247
    Eighty 223
    Eighty 359
    Eighty 280
    Eighty 141
    Ninety 210
    Ninety 305
    Ninety 290
    Ninety 286
    Ninety 175
    Ninety 225
    Ninety 200
    Ninety 224
    Ninety 290
    Ninety 210
    Ninety 235
    Ninety 223
    Ninety 176
    Ninety 170
    Ninety 217
    Ninety 170
    Ninety 290
    Ninety 190
    Ninety 220
    Ninety 140

Solutions

Expert Solution

orchestra answered 2 years ago
Next > < Previous

Related Solutions

The hydrocarbon emissions at idling speed in parts per million (ppm) for automobiles of 1980 and...
The hydrocarbon emissions at idling speed in parts per million (ppm) for automobiles of 1980 and 1990 model years are given for 20 randomly selected cars. (a) For each model year, compute the sample mean, median, mode and midrange. (b) For each model year, compute the variance and standard deviation of the data (to one decimal digit). (c) Comment on what the data indicate regarding whether or not the automobile emissions changed from 1980 to 1990. 1980 1990 140 140...
Below are the hydrocarbon emissions at idling speed, (in parts per million, ppm) of a random...
Below are the hydrocarbon emissions at idling speed, (in parts per million, ppm) of a random sample of eighteen 1990 model cars. 39 135 40 152 41 153 62 162 70 185 81 260 103 302 110 328 132 332 Use the WSRT to determine if there is sufficient evidence to indicate that the median hydrocarbon emission at idling speed is under 180 ppm. (alpha = .05).
The units of parts per million (ppm) and parts per billion (ppb) are commonly used by...
The units of parts per million (ppm) and parts per billion (ppb) are commonly used by environmental chemists. In general, 1 ppm means 1 part of solute for every 106 parts of solution. (Both solute and solution are measured using the same units.) Mathematically, by mass, ppm can be expressed as shown below. ppm = µg solute g solution = mg solute kg solution In the case of very dilute aqueous solutions, a concentration of 1.0 ppm is equal to...
What is the parts per million (ppm) of styrene in this enclosure? The enclosure is 8...
What is the parts per million (ppm) of styrene in this enclosure? The enclosure is 8 x 3 x 3 ft large. Liquid styrene accounts for 4 percent of the size of a tank within the enclosure which is 20 x 20 x 8 inches. What is the ppm of the air? Styrene has a chemical formula of C6H5CH=CH2. The density of styrene is 0.906 g/cm^3. Also, according to the cdc, for styrene, 1 ppm = 4.26 mg/m^3
The level of carbon monoxide air pollution in parts per million (ppm) is measured at an...
The level of carbon monoxide air pollution in parts per million (ppm) is measured at an entrance ramp to interstate highway I-80 near Iowa City each day. Measurements from two different samples are summarized as follows: Sample 1: n = 96 x¯ = 126.8 s = 140.2 Sample 2: n = 143 x¯ = 126.8 s = 140.2 Let µ = mean daily level of carbon monoxide pollution at the entrance ramp, in ppm • Interval 1 is a 90%...
A prescription medicine is supposed to contain an average of 250 parts per million (ppm) of...
A prescription medicine is supposed to contain an average of 250 parts per million (ppm) of a certain chemical. If the concentration is higher or lower than this, the drug may not be effective. The manufacturer runs a check to see if the mean concentration of the chemical in a large shipment conforms to the target level of 250 ppm or not. If it does not, the manufacturer will stop production (costing time and money) to remedy the situation. A...
If the reported average amount of CO2 (ppm) levels, in parts per million, in 50 kitchen...
If the reported average amount of CO2 (ppm) levels, in parts per million, in 50 kitchen gas cooking appliances was 600.1 ppm and a sample standard deviation of 95.2 ppm. a. Find a 95% confidence interval for the mean amount of CO2 in all kitchen gas cooking appliances. b. If the investigators thought the standard deviation was 130 ppm, what sample size would be neces- sary to obtain an interval with of 50 ppm for a confidence level of 95/
A prescription allergy medicine is supposed to contain an average of 245 parts per million (ppm)...
A prescription allergy medicine is supposed to contain an average of 245 parts per million (ppm) of active ingredient. The manufacturer periodically collects data to determine if the production process is working properly. A random sample of 64 pills has a mean of 250 ppm with a standard deviation of 12 ppm. Let µ denote the average amount of the active ingredient in pills of this allergy medicine. The null and alternative hypotheses are as H0: µ = 245, Ha:µ...
In clinical applications, the unit parts per million (ppm) is used to express very small concentrations...
In clinical applications, the unit parts per million (ppm) is used to express very small concentrations of solute, where 1 ppm is equivalent to 1 mg of solute per 1 L of solution. Calculate the concentration in parts per million for each of the following solutions. a) There are 39 μg of calcium in a total volume of 83 mL.​ b) There is 0.85 mg of caffeine in a total volume of 149 mL.​ c) There is 0.51 mg of...
Percent by mass to parts per million. Convert 4.45% NaOH(aq) solution to parts per million NaOH...
Percent by mass to parts per million. Convert 4.45% NaOH(aq) solution to parts per million NaOH in the solution. Do NOT assume a dilute aqueous solution! Use the molar mass of the entire salt formula, not either ion alone. The solution density is 1.047 g/mL. Answer to 3 significant figures with appropriate units.
ADVERTISEMENT
Subjects
ADVERTISEMENT
Latest Questions
ADVERTISEMENT