Car speeds John Beale of Stanford, CA, recorded thespeeds of cars driving past his house, where the speedlimit was 20 mph. The mean of 100 readings was23.84 mph, with a standard deviation of 3.56 mph. (Heactually recorded every car for a two-month period.These are 100 representative readings.)a) How many standard deviations from the mean woulda car going under the speed limit be?b) Which would be more unusual, a car traveling 34 mphor one going 10 mph?

The heights of Crepe Myrtle saplings at a local nursery are measured and the data recorded. The data is then plotted and the distribution is found to be bell-shaped. The mean of the set is 67 inches and the standard deviation is 3 inches. A graph of the situation is shown below: 58 61 64 67 70 73 76 a) What percentage of the saplings is more than 70 inches tall? b) What percentage of the saplings is between 61 and 73 inches tall?

The average driver spends $54 at the gas station each week with a standard deviation of $8. Assuming that the amount a driver spends on gas follows a normal distribution, solve for the percentage of drivers who spend: 1. More than $40? 2. Less than $30? 3. Between $30 and $40

questions: d- f e. > or ≤ f. a. accept b. reject c. fail to reject

Which statement below is correct? a. Standard deviation should be used when calculating z for a single score, while standard error should be used when calculating z for a sample mean. b. When calculating z for a single score or for a sample mean, the standard error should be used. c. Standard error should be used when calculating z for a single score, while standard deviation should be used when calculating z for a sample mean. d. When calculating z for a single score or for a sample mean, the standard deviation should be used.

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…

The average weight of a certain car after production is 3000 pounds with a standard deviation of 400 pounds.  Cars in the upper 6% of the weight class have to be inspected again before being sold.  At what weight do the cars have to start being inspected? Round to the nearest pound.

Use the following information for the question. The average travel time to work for a person living and working in Kokomo, Indiana is 17 minutes. Suppose the standard deviation of travel time to work is 4.5 minutes and the distribution of travel time is approximately normally distributed.Which of these statements is asking for a measurement (i. e. is an inverse normal question)?   A.What percentage of people living and working in Kokomo have a travel time to work that is between thirteen and fifteen minutes?   B.If 15% of people living and working in Kokomo have travel time to work that is below a certain number of minutes, how many minutes would that be?

Both sets of values have an average of 13. Is set As standard deviation smaller, larger, or about the same as set abs? set A: 1 2 3 23 24 25 set B: 8 10 12 14 16 18