Suppose that the proportion of high blood cholesterol level of U.S. children is known to be 0.78. Ho: ??:

You are interested in comparing sleep habits of elementary school children.  Suppose you have agroup of eighth graders. You asked them in July to estimate about how many hours of sleep they get pernight, on average. You asked those same individuals the same question again in November, during theschool year. Which is the most appropriate test to use?

Español According to previous studies, 10% of the U.S. population is left-handed. Not knowing this, a high school student claims that the percentage of left-handed people in the U.S. is 12%. The student is going to take a random sample of 900 people in the U.S. to try to gather evidence to support the claim. Let p be the proportion of left-handed people in the sample. Answer the following. (If necessary, consult a list of formulas.) (a) Find the mean of p. 0.12 (b) Find the standard deviation of p. X 5 (c) Compute an approximation for P(p≤0.12), which is the probability that there will be 12% or fewer left-handed people in the sample. Round your answer to four decimal places. A 27

A reader wrote in to the “Ask Marilyn” column in Parade magazine to say that his grandfather told him that in three-quarters of all baseball games, the winning team scores more runs in one inning than the losing team scores in the entire game. (This phenomenon is known as a “big bang.”) Marilyn responded that this proportion seemed too high to be believable. Let p be the proportion of all major-league baseball games in which a “big bang” occurs. To investigate this claim, we randomly selected one week of the 2006 major-league baseball season, which turned out to be July 31-August 6, 2006. Then we examined the 95games played that week to determine which had a big bang and which did not. Of the95 games in our sample, 47 contained a big bang. Use a two-sided alternative, state the null and alternative hypothesis (in symbols and in words) for testing Marilyn’s claim. 7. Determine the test statistic and p-value. 8. What conclusion would you draw concerning Marilyn’s conjecture using the…

A 2010 Pew Research poll asked 1,306 Americans "From what you've read and heard, is there solid evidence that the average temperature on earth has been getting warmer over the past few decades, or not?". The table below shows the distribution of responses by party and ideology, where the counts have been replaced with relative frequencies.   Earth is warming Not warming Don't know (or refuse) Total Conservative Republican 0.11 0.2 0.02 0.33 Mod/Lib Republican 0.06 0.06 0.01 0.13 Mod/Cons Democrat 0.25 0.07 0.02 0.34 Liberal Democrat 0.18 0.01 0.01 0.2 Total 0.6 0.34 0.06 1 a) Are believing that the earth is warming and being a liberal Democrat mutually exclusive?  not mutually exclusive  mutually exclusive Incorrect b) What is the probability that a randomly chosen respondent believes the earth is warming or is a liberal Democrat?  (please round to four decimal places)c) What is the probability that a randomly chosen respondent believes the earth is warming given…

The price of a share of stock divided by the company's estimated future earnings per share is called the P/E ratio. High P/E ratios usually indicate "growth" stocks, or maybe stocks that are simply overpriced. Low P/E ratios indicate "value" stocks or bargain stocks. A random sample of 51 of the largest companies in the United States gave the following P/E ratiost. 9 20 11 35 19 13 15 21 29 53 16 26 21 14 21 27 10 12 47 14 40 18 60 72 33 14 8 49 5 16 8 19 12 31 67 51 26 18 17 20 19 13 25 23 27 44 20 27 19 18 32 (a) Use a calculator with mean and sample standard deviation keys to find the sample mean x and sample standard deviation s. (Round your answers to one decimal place.) (b) Find a 90% confidence interval for the P/E population mean u of all large U.S. companies. (Round your answers to one decimal place.) lower limit upper limit (c) Find a 99% confidence interval for the P/E population mean u of all large U.S. companies. (Round your answers to one decimal place.) lower limit upper…

Oxygen consumption was measured in twelve individuals while they sat with their eyes closed listening to an exciting adventure story read by Taylor Swift or a restful instrumental medley performed by Metallica. Based on the results shown, is oxygen consumption less when listening to the music?                                     Story                           Music                           6.1                               5.4                         7.2                               6.7                         5.7                               5.4                         6.4                               4.2                         5.8                               4.0                         6.2                               4.1

3. The table below shows the expected years of schooling and gross domestic product (GDP) of the Southeast Asian countries in 2017. Use this information to answer the following: 1. Determine the correlation between the expected years of schooling and GDP. II. Based on the result, what can you conclude about the relationship between the expected years of schooling and GDP? Country Expected Years of Schooling GDP per capita (in international-$) Brunei 14.5 71809.3 Cambodia 11.7 3645.1 Indonesia 12.8 11188.7 Laos 11.2 6397.4 Malaysia 13.7 26808.2 Myanmar 10 5591.2 Philippines 12.6 7599.2 Singapore 16.2 85535.4 Thailand 14.7 16277.7 Vietnam 12.7 6171.9 Source: https://ourworldindata.org/grapher/expected-years-of-schooling-vs-qdp-per-capita

In 2001, the polls found that 81% of American adults believed that there was a conspiracy in the death of President Kennedy. Assume a recent poll asked 1160 American adults if they believe there was a conspiracy in the assassination and it found that 897 believe there was a conspiracy. Does the data show that the proportion of Americans who believe in this conspiracy is now lower? Test at the 9% level.      What is the correct parameter symbol for this problem?  What is the wording of the parameter in the context of this problem? Fill in the correct null and alternative hypotheses:

Education influences attitude and lifestyle. Differences in education are a big factor in the "generation gap." Is the younger generation really better educated? Large surveys of people age 65 and older were taken in n1 = 38 U.S. cities. The sample mean for these cities showed that x1 = 15.2% of the older adults had attended college. Large surveys of young adults (age 25 - 34) were taken in n2 = 37 U.S. cities. The sample mean for these cities showed that x2 = 18.1% of the young adults had attended college. From previous studies, it is known that ?1 = 6.4% and ?2 = 4.8%. Does this information indicate that the population mean percentage of young adults who attended college is higher? Use ? = 0.05. (c) Find (or estimate) the P-value. (Round your answer to four decimal places.) A random sample of n1 = 12 winter days in Denver gave a sample mean pollution index x1 = 43. Previous studies show that ?1 = 15. For Englewood (a suburb of Denver), a random sample of n2 = 16 winter days gave a…