The brain volumes (cm³) of 50 brains vary from a low of 904 cm³ to a high of 1486 cm³. Use the range rule of thumb to estimate the standard deviations and compare the result to the exact standard deviation of 164.5 cm³, assuming the estimate is accurate if it is within 15 cm³. The estimated standard deviation is cm³. (Type an integer or a decimal. Do not round.)

The mean score on a driving exam for a group of drivers education students is 72 points with a standard deviation of 6 points. apply Chebyshev theorem  to the data using K=2. Interpret the results. Simplify answer.

The average birth weight of elephants is 250 pounds. Assume that the distribution of birth weights is Normal with a standard deviation of 40 pounds. Find the birth weight of elephants at the 90th percentile.

Listed in the data table are IQ scores for a random sample of subjects with medium lead levels in their blood. Also listed are statistics from a study done of IQ scores for a random sample of subjects with high lead levels. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Click the icon to view the data table of IQ scores. a. Use a 0.05 significance level to test the claim that the mean IQ scores for subjects with medium lead levels is higher than the mean for subjects with high lead levels. What are the null and alternative hypotheses? Assume that population 1 consists of subjects with medium lead levels and population 2 consists of subjects with high lead levels. X A. Ho: H₁ H₂ H₁ H₁ H₂ c. Ho: M₁ = H₂ H₁: H₁ H₂ The test statistic is 0.56. (Round to two decimal places as needed.) The P-value is (Round to three decimal…

Assume that the mean height of men in the United States is 70 inches, with a standard deviation of 3 inches.  A particular man is 80 inches tall.  Find the z-score of his height.  (Round to two decimal places.)

Assume that the distribution of scores on a college entrance exam is normally distributed with a mean of 490 and a standard deviation of 43. For each score in the table below, convert the raw score into a corresponding z-score. original score Z-score 621 398 586 710

Use the Weibull distribution to model ocean wave heights. Assume that the mean wave height at the observation station is 2.5 meters and the shape parameter equals 2. Determine the standard deviation of wave height.

Help me find which A,B,C, or D is the correct answer to the last part please. The brain volumes ​(cm3​) of 50 brains vary from a low of 904 cm3 to a high of 1490 cm3. Use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 191.4 cm3​, assuming the estimate is accurate if it is within 15 cm3. The estimated standard deviation is 146.5 cm3.     A. The approximation is not accurate because the error of the range rule of​ thumb's approximation is greater than 15 cm3.   B. The approximation is not accurate because the error of the range rule of​ thumb's approximation is less than 15 cm3.   C. The approximation is accurate because the error of the range rule of​ thumb's approximation is greater than 15 cm3.   D. The approximation is accurate because the error of the range rule of​ thumb's approximation is less than 15 cm3.

Assume that the readings at freezing on a batch of thermometers are normally distributed with a mean of 0°C and a standard deviation of 1.00°C. A single thermometer is randomly selected and tested. Find P50, the 50-percentile. This is the temperature reading separating the bottom 50% from the top 50%. Round to 3 decimal places.