Alcohol is claimed to be a factor in 39% of all fatal car accidents in the United States. The town police chief is reviewing a random sample of 55 local car accident records to compare to the national data. How many of the sample records need to show alcohol as a factor to suggest a significant difference exists between the national and local rate of alcohol related car accidents? Explain using standard deviations.

Q: A pharmaceutical company claims that a drug is effective in treating 90% of people having severe…

A: Given that,The random variable follows binomial distribution,n=6p=90%=0.9,q=1-p, q= 0.1

Q: On the past math summative exam, the bottom 20% of students failed to pass the test. The mean for…

A: The mean for the test is, μ=55 The standard deviation is σ=11 Consider that the bottom 20% of…

Q: The number of goals scored by a college soccer team for a given season are 4, 9, 0, 1, 3, 12, 3, 7,…

A: The population mean is, μ=∑xN=4+9+0+1+3+12+3+7+4+5+8+212=5812=4.8333 The population mean is 4.8333.

Q: After entering the test scores from her Statistics class of 25 students, the instructor calculated…

A: IQR is obtained as the difference between the third and first quartiles.

Q: In a sample of 152 people the average score was 74 with a standard deviation of 6. What is the…

A: Sample size = n = 152   Mean = 74  Standard deviation = 6

Q: What is the standard deviation on the graph ?

A:

Q: The number of minutes spent reading in one day is normally distributed with a mean of μ = 23 and a…

A: The normal distribution:A continuous random variable X is said to follow normal distribution if the…

Q: The year Ali graduated college, he got a job as an entry-level software engineer working for a firm…

A: Solution

Q: An advertising agency has stated that 20% of all television viewers watch a particular program. How…

A: From the provided information, An advertising agency has stated that 20% of all television viewers…

Q: The standard deviation of 15 scores was 5 and the mean was 85. What was the variance?

A: We have given that  N=15 Mean=85 Standard deviation=5 Note: According to Bartleby Expert guidelines,…

Q: statistics professor reported that the mean score in a recent quiz is 72 and the standard deviation…

A: Solution

Q: If the main level of snowfall for Boston Massachusetts is 44 inches per year and the standard…

A:

Q: Does a small standard deviation signify more or less uncertainty in the data ? Explain.

A:

Q: Recently, a random sample of 25–34 year olds was asked, "How much do you currently have in savings,…

A: From the different savings class we need to find first the class mid point(xi) . And the frequency…

Q: What is the effect size?

A: We have to calculate effect size for testing of single mean.

Q: A recent Gallop Poll indicates that 80 % of voting age adults disapprove of Congress. If 700 voting…

A: Let p be the probability that a voting age adult disapproves of Congress. Given that p = 0.80 Let X…

Q: A particular leg bone for dinosaur fossils has a mean length of 5 feet with a standard deviation of…

A: Given, A particular leg bone for dinosaur fossils has a mean length of 5 feet with a standard…

Q: statewide, social workers average 10.2 years of experience. In a random sample, 203 social workers…

A: State the hypotheses.

Q: Suppose the exam average in a class is 48% with a standard deviation of 15. What proportion of…

A:

Q: The year Deon graduated college, he got a job as an entry-level software engineer working for a firm…

A:

Q: The golf scores for a school team were normally distributed with a mean of 68 and a standard…

A: Let X be the golf scores. It is given that X is normally distributed with mean 68 and standard…

Q: Seventy-four percent of Americans favor spending government money to develop alternative sources of…

A:

Q: What is the difference between what the z score measures and what the standard deviation measure?

A: z score is standard score and the formula for finding z score is,

Q: An incoming freshman took her college’s placement exams in French and mathematics. In French, she…

A:

Q: If the highest paid soccer platyer has his salary doubled, which of these will change? Can you…

A: We have to find correct options which will change.

Q: The mean grade of Adrian in the standard deviation was 7. In Science, his mean grade was 89 and the…

A:

Q: If research samples 28 college students and wants to compare the sample mean of 8 to the population…

A: From the provided information, Sample size (n) = 28 Sample mean (x̄) = 8 Population mean (µ) = 12…

Q: in a group of 230 tests, how many students score within one standard deviation of the mean?

A: The probability that the students score within one standard deviation of the mean will be:…

Q: Ninety nine percent of scores fall between 3 and -3 standard deviations from the mean.  True or…

A: The empirical rule is helpful for interpreting the values for a standard deviation. According to…

Q: A student will spend 15 hours average each week in class. If the standard deviation is 2 hours, what…

A: Given that mean=15 and standard deviation = 2 Let, X= number of hours spent by a student in the…

Q: Employees at Executive Management Co. spend an average of 80 minutes on the phone each day. If the…

A:

Q: Vivino website, suppose the mean price for a bottle of red wine that scores 4.0 or higher on the…

A: Given: Sample mean x¯=30.15 Sample standard deviation (s) =  12 Sample size (n) = 59 Hypothesized…

Q: Describe  the scores in a sample  that has a standard  deviation of zero

A: If the standard deviation is zero there will be no dispersion of scores from the Mean. It means that…

Q: Coronary bypass surgery: The Agency for Healthcare Research and Quality reported that 53% of people…

A:

Q: According to the U.S. Census, the average adult woman is the United States is 65 inches tall and the…

A: Given X is normal Distributed with mean µ = 65.0 and standard deviation σ = 3.0 Need to find Z score…

Q: Five students took a self-confidence test. Their deviation scores were –4, +3, +1, –2, and +2.…

A: Given ,deviation scores were –4, +3, +1, –2, and +2

Q: On the past mathematics test, the bottom 20% of students failed to pass the test. The mean for the…

A: The mean of the data is μ=55 and the standard deviation is σ=11 It is also given that 20% of…

Q: 9. Explain the similarities and differences between standard deviation and IQR. When might one be…

A:

Q: A student scored 66 on a general science test where the class mean and standard deviation were 82…

A:

Q: A biologist found the wingspans of a group of monarch butterflies to be normally distributed, with a…

A: Given,Mean (μ) = 52.2Standard deviation (σ) = 2.3a) Required probability is…

Q: In a survey of women in Canada, the mean height was 65 inches with a standard deviation of 3 inches.…

A:

Q: Jeffrey, as an eight-year old, established a mean time of 16.43 seconds for swimming the 25-yard…

A: Population mean = ? = 16.43 Population S.D = ? =0.8 Sample size = n =15 Sample mean = x̅ = 16

Q: What is the correct conclusion?   A recent study found that 61 children who watched a commercial for…

A:

Q: The average on the Math section of the SAT was 500 with a standard deviation of 100. What score must…

A:

Q: A researcher in Des Moines, Iowa sampled 56 households and found the mean number of puppies per…

A: # sample size n=56  population mean mu=3.03  standard deviations=1.5  then to find 62nd percentile…

Q: The average price of a personal computer is $949. If the computer distributed with a standard…

A:

Q: Would it be reasonable to use the standard deviation formula?

A: here  According to a gallup survey of boys 77% of boys had played computer games in the past week…

Q: recent study found that 61 children who watched a commercial for potato chips featuring a celebrity…

A:

Q: there are 75 students in the class and 20 students are getting a+ grade in the class find the mean…

A:

Q: In a study of Ridge View's boys' basketball team, the average height is 68 inches and standard…

A: Given that, In a study of Ridge view's boys' basketball team, the average height is 68 inches and…