In a recent year,  27% of all cars purchased were black in color.  A manufacturer thinks that percentage has decreased.  A random sample of 300 new car purchases had 70 black cars.  Test the researcher's claim at the αα=0.1 significance level.

In 2015, a survey found that 38% of Americans were supportive of online education for elementary and secondary education. With the increase in contagious viruses, it is of interest if this proportion has changed. In a 2019 poll, 51% of 1028 Americans were supportive of online education for elementary and secondary education. At the 10% significance level, do the data provide sufficient evidence to conclude that the percentage of all American adults who support online education for elementary and secondary education has changed from what was believed in 2015? Choose the choice that gives the null and alternative hypothesis.

Do adults (age 20–45) with children and adults without children have the same distribution of type of vehicle that is driven? In a large city, 130 randomly selected adults with children and 170 randomly selected adults without children were asked which type of car best describes the vehicle they primarily drive: car, truck, van, or SUV. A significance test will be conducted using the data to determine if there is convincing evidence at α = 0.05 that the distribution of type of vehicle driven differs between adults (age 20–45) with children and adults without children. What are the hypotheses for this test? H0: There is  in the distribution of vehicle type driven between adults (aged 20–45) with children and adults without children. Ha: There is  in the distribution of vehicle type driven between adults (aged 20–45) with children and adults without children.

Data from the Department of Motor Vehicles indicate that 80% of all licensed drivers are older than age 25. In a sample of n = 50 people who recently received speeding tickets, 33 were older than age 25 and the other 17 were age 25 or younger. Is the age distribution for this sample significantly different from the distribution for the population of licensed drivers? Use alpha = .05.   In a sample of n = 50 people who recently received parking tickets, 36 were older than age 25 and the other 14 were age 25 or younger. Is the age distribution for this sample significantly different from the distribution for the population of licensed drivers? Use alpha = .05.

A psychologist is interested in people’s assessment of life happiness and how it relates to positive lifestyle changes. The researcher randomly assigns 42 individuals to one of two groups: Exercise Only, and Exercise and Healthy Eating. The researcher believes that Group 1 (n = 21; Exercise and Healthy Eating) will be significantly happier than Group 2 (n = 21; Exercise Only). Perform the correct test of significance, with alpha = .05. Be sure to write out your hypotheses and final decision.

A researcher conducts a between-subjects study to determine whether low levels of the neurochemical serotonin leads to an increase in aggression. One sample of rats serves as a control group and receives a placebo that does not affect normal levels of serotonin. A second sample of rats receives a drug that lowers brain levels of serotonin. Using an alpha level of a = .05, the researcher then tests the animals by recording the number of aggressive responses each of the rats display. The data are as follows: a.) Step 1: State the Hypotheses Ho: H₁: Control n = 10 M = 14 SS=180.5 b.) Step 2: Determine the critical region and draw it on the distribution above: df = > *critical SM₁-M₂ Low Serotonin n = 15 M = 19 SS = 130.0 c.) Step 3: Calculate the test statistic using the provided sample data: tobs d.) Step 4: Make a decision. Circle one: Reject Null (Ho) or Fail to Reject Null (Ho) e.) State your conclusions about the research scenario in sentence form: d= f.) What is the estimated effect…

The drug Ritalin is designed to stimulate the central nervous system. In a random sample of 252 boys aged ten – twelve years old, it was found that 44 of the boys were taking Ritalin. It is known that the proportion of all boys aged 13 – 15 who take Ritalin is 24%. A researcher claims that the population proportions of boys who take Ritalin aged 10 – 12 is different than boys aged 13 – 15. Can you support this claim at the 5% significance level? a. Conduct a hypothesis test to test the claim at the 5% significance level. Be sure to state you Ho and Ha, your test statistic and p-value, whether or not you reject Ho and whether you support the claim. b. Show that you can use the large sample methodology. c. Write a complete sentence describing what a Type I error is in context.

A researcher was interested in comparing the resting pulse rate of people who exercise regularly and people who do not exercise regularly. Independent random samples of 16 people aged 30-40 who do not exercise regularly (sample 1) and 12 people aged 30-40 who do exercise regularly (sample 2) were selected and the resting pulse rate of each person was measured. The summary statistics are as follows: Pulse Rate data   Group 1 (no exercise) Group 2 (exercise) average 72.7 69.7 standard deviation 10.9 8.2 sample size 16 12 Test the claim that the mean resting pulse rate of people who do not exercise regularly is greater than the mean resting pulse rate of people who exercise regularly, use 0.01 as the significance level. Round you answer to 3 decimal places. Group of answer choices p-value=0.207, evidence not support claim p-value=0.267, evidence support claim p-value=0.414, evidence not support claim p-value=0.793, evidence not support claim p-value=0.207, evidence…