A magazine asked 1000 adults to identify their favorite pie. 14±3% chose chocolate pie. Which confidence interval is wider: 99% or 80%? C. A 99% confidence interval must be wider than an 80% confidence interval in order to be more confident that it captures the true value of the population proportion.
Probability that a student who did not complete homework passed a test, given data table of students who passed/failed test and completed/did not complete homework.
Find total variation for predicted data (0,8),(1,5),(2,2) from line of best fit y′=8−3x. Provide actual observed data points to calculate total variation.
Find the SAT score that corresponds to the 26th percentile, given that SAT scores are normally distributed with a mean of 1090 and a standard deviation of 197. SAT score=1090+197×z, where z is the z-score corresponding to the 26th percentile.
Compute the mean, median, and mode of repair costs for 4 crashes of the same car model at 5 mph. The repair costs are 429,448, 486,and222.
A. The mean cost of repair is $396.25. (Round to the nearest cent as needed.)
Find the probability that a randomly chosen 10-year-old in the US has height between 39.9 and 46.4 inches, given heights are normally distributed with mean 55.7 inches and standard deviation 9 inches. Round final answer to 3 decimal places.
Around what percentage of adults in the USA have stage 2 high blood pressure (SBP≥160) given that SBP is normally distributed with μ=122 and σ=16? Round to two decimal places.
Find the five-number summary and interquartile range for the distances (in miles) to the nearest airport for 11 families: 8,13,19,19,21,23,28,28,31,37,42.
Find the probability that Victoria's next bowling score, which is normally distributed with μ=130 and σ=11, falls between 123 and 130. Round the answer to the nearest whole percent.
Analyze the given stem-and-leaf plot to find the mean, median, standard deviation, and range of the data, rounding answers to one decimal place. a. Mean: n∑x
b. Median: The middle value when the data is ordered
c. Standard Deviation: n∑(x−μ)2
d. Range 50: The difference between the 50th percentile and the 50th percentile
Chemical engineer must report the average volume of a pollutant produced by plants. Data: Platte 2.772 L, Macon 48.58 L, South Fork 2.36 L. What average volume should be reported with correct significant digits?
Which measure of central tendency is most affected by the extreme value in the given half marathon pace data? {6.7,7.1,7.5,7.6,3.3,7.4,7.2,7.4,7.1,7.4,6.8,6.9,7.3}
Find the 43rd and 53rd percentiles of the ages of 29 Academy Award winning best actors, given in ascending order: 24,27,27,30,30,36,37,37,37,39,42,45,46,47,48,49,50,51,51,56,61,63,64,69,70,71,77,78,78.
Babies with low birth weight (< 2500 g) may have health issues. Mean birth weight is 3496 g, but 2646 g for babies born 1 month early. Find standardized score (z-score) for 2500 g birth weight for: a) all births, b) 1 month early births. Determine which group 2500 g is more common. a. z=−2.17
b. z=−0.32
c. B. A birth weight of 2500 g is more common for all births in the country.
Rewrite the problem statement: Find the frequency distribution and construct a histogram for the hottest recorded temperatures (in °F) across 16 North American cities. 92.5−96.5: □96.5−100.5: □100.5−104.5: □104.5−108.5: □108.5−112.5: □
Calculate the range, variance, and standard deviation for the given samples. a. 34,47,45,40,48, b. 100,3,9160,16207, c. 100,35,40,6040,447. a. The range is □.
Compare the z-scores of a 45-year-old Best Actor and a 37-year-old Best Supporting Actor with μBA=44.0, σBA=7.2, μBSA=54.0, and σBSA=16. Best Actor: z=7.245−44.0=0.14
Best Supporting Actor: z=1637−54.0=−1.06
Classify variables as quantitative or categorical: (a) customer satisfaction (very/somewhat satisfied/dissatisfied), (b) weight (in lbs) needed to break bridge cable, (c) cell phone service provider.
A manufacturer claims the mean breaking strength of new cables is greater than 1775 lbs. Test this claim using a one-tailed test with α=0.05. The sample mean is 1790 lbs and the population standard deviation is 55 lbs. (a) H0:μ≤1775 lbs, H1:μ>1775 lbs
(b) Use a z-test
(c) Test statistic z=σ/nxˉ−μ=1.818
(d) p-value =0.035
(e) Yes, we can support the claim that the mean breaking strength is greater than 1775 lbs.
Given normal calorie burn data with μ=310 and σ=7, find probabilities of: (a) >320 calories, (b) <302 calories, (c) 298-330 calories. The probability of (b) is 12.70%, and the probability of (c) is □.
Determine the most accurate and precise measurements of signal speed in a nerve fiber, given a later reliable measurement of 16.0m/s and four teams' earlier measurements.
Approximate the mean gas mileage (in miles per gallon) from a frequency distribution of 23 cars. Round the mean to one decimal place. 25−30:9,31−36:10,37−42:1,43−48:3
A manufacturer's item lengths are normally distributed with μ=14.2 inches and σ=2.3 inches. Find the probability that the mean length of 35 randomly chosen items exceeds 13.6 inches. (Round to 4 decimal places)
The mean age of lead actors from the top ten grossing movies of 2007 was 36.4 years with a standard deviation of 9.87 years. Assume the distribution is approximately unimodal and symmetric. According to the Empirical Rule, the ages of nearly all lead actors will be between $16.7;56.1$ years. Adrien Brody, who was 29 years old when he won the academy award in 2002, was within this range.
Generate a scatter plot with regression equation y=32.73x+15.14 and r=0.044. What proportion of variation in y can be explained by the regression? Round to 3 decimals. What is the symbol for this calculation? What is this term called?
The company retires cars based on miles, purpose, and style. The car fleet's service duration follows a normal distribution with μ=62 months and σ=5 months. What is the approximate percentage of cars in service between 47 and 57 months?
The university's physical plant receives daily requests to replace fluorescent lightbulbs. The distribution of requests follows a normal distribution with μ=59 and σ=10. Using the Empirical Rule, find the percentage of requests between 39 and 59. ans = 68.27%
Calculate the standard error of the sample proportion p^ for n=100 and various values of p. Observe how the standard error changes as p approaches 0 or 1.
Find the degrees of freedom, critical values χL2 and χR2, and σ confidence interval for a normal distribution sample with n=149,s=1.95 (1000 cells/μL) at 99% confidence.
Engineers must design helmets to fit the normal distribution of male head breadths with μ=6.1-in and σ=1.2-in. Find the middle 99% of head breadths: Between 3.71-in and 8.49-in. Find the middle 99% of sample averages for head breadths of size 60: Between 5.86-in and 6.34-in.
Determine if half of all teens aged 13-17 have made new friends online using a 0.05 significance level and the normal distribution. H0:p=0.5H1:p=0.5
Polygraph experiment has 99 results: 22 wrong, 77 correct. Test if correct results are <80% using 0.05 significance. Find null/alt hypotheses, test statistic, P-value, conclusion. H0:p=0.80,H1:p<0.80
Test statistic z=−0.55
P-value = 0.2912 (rounded to four decimal places)
Determine the total number of subjects, the number who did not use marijuana, and the probability a random subject did not use marijuana given drug test results. Total subjects: □
Subjects who did not use marijuana: □
Probability a random subject did not use marijuana: □
In Alabama, 44% of the population favors the incumbent for governor. Find the probability that at least 72 out of 150 randomly sampled respondents favor the incumbent, using a normal approximation with continuity correction. X∼Binomial(n=150,p=0.44) P(X≥72) Y∼Normal(μ=66,σ=5.24) P(Y≥71.5) Use continuity correction Probability: 0.8001
Estimate the proportion of oil tankers that had spills given a sample of 712 tankers, where 570 did not have spills. Enter the result as a fraction or decimal rounded to 3 decimal places.
Find the number of classes and their lower/upper class limits given the minimum, maximum, and class width. minimum=9,maximum=80,number of classes=7 The class width is 11. Find the lower class limits and upper class limits.
Determine if the events "the person is female" and "the person prefers classic rock" are independent. Justify your answer based on the provided 2×4 contingency table.
Find the expected value of a randomly chosen student's score on last year's final exam given the score distribution. X = score of a randomly chosen student
Expected value of X = 10(19×3)+(35×3)+(60×4)
Construct a grouped frequency distribution for the ages of presidents at inauguration, using classes of width 5 starting from 41-45. Provide the frequency value for each class. 41−45:□46−50:□51−55:□56−60:□61−65:□66−70:□
Determine the number of college students who got news from only social media using a Venn diagram. Given: 94 students surveyed, 32 from news websites, 25 from social media, and 11 from both. n( News websites only )=21n( Social media only )=14
Determine the sample size needed to estimate the proportion of a population with a genetic marker, with 99% confidence and 1.5% margin of error, given the expected proportion is 80%. n=E2zα/22p∗(1−p∗)
Find the midquartile of football league passer ratings, where Midquartile = (Q1+Q3)/2. The ratings are: 99.7, 95.7, 89.2, 84.7, 83.3, 82.4, 78.5, 77.8, 76.3, 74.4.
Determine the mean and standard deviation of the sampling distribution of the proportion of voters supporting a candidate in a county, given the population proportion and sample size. Mean: μp=0.2700
Standard error: σp=0.0226
Poisson regression uses PMF p(y∣λ)=y!λye−λ. 1. Find loss ℓi(β) and its gradient. 2. Prove Rn(β) is convex. 3. Show Fη(β^)=β^ at minimizer. 4. Implement gradient descent to estimate β^ and compare with true β.