Standard deviation - math word problems

Number of problems found: 26

  • Controller
    std_dev Output Controller of the company in the control of 50 randomly selected products found that 37 of them had no defect 8 has only one flaw, three had two defects, and two products had three defects. Determine the standard deviation and coefficient of variat
  • Energy
    energy In one region, the September energy consumption levels for single-family homes are found to be normally distributed with a mean of 1050 kWh and a standard deviation of of 218 kWh. Find the consumption level separating the bottom 45% from the top 55%.
  • IQ Intelligence quotient
    normal_d_1 Intelligence quotient (IQ) is a standardized score used as the output of standardized intelligence psychological tests to quantify a person's intelligence with the rest of the population (respectively to a given group). Intelligence has an approximately n
  • Standard deviation
    standard-dev_1 Find standard deviation for dataset (grouped data): Age (years) No. Of Persons 0-10 15 10-20 15 20-30 23 30-40 22 40-50 25 50-60 10 60-70 5 70-80 10
  • Life expectancy
    normal_d The life expectancy of batteries has a normal distribution with a mean of 350 minutes and standard deviation of 10 minutes. What the range in minutes 68% of the batteries will last? What is the range in minutes approximately 99.7% of batteries will last?
  • US GDP
    stat_2 Consider the following dataset , which contsins the domestic US gross in millions of the top grossing movie over the last 5 years. 300,452,513,550,780 I. Find the Mean of the Dataset II. Find the Squared deviation of the second observation from the mean I
  • Std-deviation
    standard-dev Calculate standard deviation for file: 63,65,68,69,69,72,75,76,77,79,79,80,82,83,84,88,90
  • A mountain
    rope_normal_stdev A mountain climber plans to buy some rope to use as lifeline. Which of the following would be the better choice? Explain your choice. Rope A: Mean breaking strength:500lb; standard deviation of 100lb Rope B: Mean breaking strength: 500lb; standard deviati
  • Assembly time
    mean_normal The assembly time for the toy follows a normal distribution with a mean of 75 minutes and a standard deviation of 9 minutes. The company closes at 5 pm every day. If one starts assembling at 4 pm what is the probability that he will finish before the comp
  • Stoaches
    normal_d_2 Stoaches are fictional creatures distantly related to bigfoot and yeti. Stoach weights are normally distributed, with mean 904g and standard deviation 104g. State the probability that the sample mean of a random sample of 36 stoach weights exceeds 943g. (
  • Tallest people a
    normal_d As a group, the Dutch are amongst the tallest people in the world. The average Dutchman is 184 cm tall. If a normal distribution is appropriate, and the standard deviation for Dutchmen is about 8 cm, what is the percentage of Dutchmen will be over 2 metre
  • Normal Distribution
    normal_d At one college, GPA's are normally distributed with a mean of 3.1 and a standard deviation of 0.4. What percentage of students at the college have a GPA between 2.7 and 3.5?
  • SD - mean
    normal_sd The mean is 10 and the standard deviation is 3.5. If the data set contains 40 data values, approximately how many of the data values will fall within the range of 6.5 to 13.5?
  • Statistical survey
    statistics Write TRUE OR FALSE for each question: 1 Standard deviation is a measure of central location. 2. The most frequent observation in a data set is known as the mode. 3 The most passive method of data collection is observation. 4 Access time for secondary dat
  • Alopecia
    alopecia Medical literature indicates that 45% of men suffer from alopecia. For random sample of 8 men, calculate the probability that: (a) exactly four men suffer from alopecia. (b) at most two men suffer from alopecia.
  • Marketing
    statistics Year; money spent on advertising; profit 2008 2 12 2009 5 20 2010 7 25 2011 11 26 2012 15 40 1. draw a scatter diagram depicting the data. 2. calculate the Pearson's correlation coefficient. 3. determine the linear regression equation.
  • Ball bearings
    normal_d One bearing is selected from the shipment of ball bearings. It is known from previous deliveries that the inner bearing radius can be considered as a normal distribution of N (µ = 0.400, σ2 = 25.10^−6). Calculate the probability that the selected radius w
  • Lifespan
    normal_d The lifetime of a light bulb is a random variable with a normal distribution of x = 300 hours, σ = 35 hours. a) What is the probability that a randomly selected light bulb will have a lifespan of more than 320 hours? b) Up to what value of L hours can the
  • Normal distribution GPA
    normal_d_3 The average GPA is 2.78 with a standard deviation of 4.5. What are students in the bottom the 20% having what GPA?
  • Complaints
    statistics The table is given: days complaints 0-4 2 5-9 4 10-14 8 15-19 6 20-24 4 25-29 3 30-34 3 1.1 What percentage of complaints were resolved within 2weeks? 1.2 calculate the mean number of days to resolve these complaints. 1.3 calculate the modal number of day

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