Question 10: The length of needles produced by a machine has a standard deviation of 0.03 inches. Assuming the distribution is normal, how large of a sample is needed to determine, within a margin of error of 0.008 inches, the mean length of all needles produced to 9 Answer:

The blood pressure in millimeters was measured for a large sample of people. The average pressure is 140 mm, and the SD of the measurements is 20 mm. The histogram looks reasonably like a normal curv Use the normal curve to estimate the following percentages. Choose the answer that is closest to being correct. A 19.1% B 30.9% C 38.2% D 69.1% E 68.27% A The percentage of people with blood pressure between 130 and 150 mm. B The percentage of people with blood pressure between 140 and 150 mm. D The percentage of people with blood pressure over 150 mm.

Find mean & standard deviation using table:   X Frequency 2 20% 5 10% 8 15% 10 30% 12 25% For the mean, i get 7.4 & 20%. Std dev i get 4.459362. Just wanted to check my numbers.

A variable is normally distributed with mean 34 and standard deviation 11. Use the Cumulative Z-Score Table to answer the following questions. Write your answers in decimal form using 4 decimal places. a) Find the area under the normal curve to the left of the data value 63.7. b) Find the area under the normal curve to the left of the data value 2.1. c) Find the area under the normal curve to the right of the data value 30.7. d) Find the area under the normal curve to the right of the date value 29.05. e) Find the area under the normal curve between the data values 2.1 and 29.05.

Solve this problem to find the sample standard deviation

The attached plots were constructed using a sample of 272 observations. Each observation gives the elapsed time (in minutes) of an eruption of Old Faithful geyser in Yellowstone national park. d. A sample of 6 durations have values: 4.850, 2.200, 2.900, 4.367, 1.750, 3.966. What is the mean of this sample? e. What is the standard deviation of the sample in d. if ∑ni=1x2i=74.635∑i=1nxi2=74.635?( attached as pic) f. Give the shape and parameters of the sampling distribution of the sample mean when n=272n=272 if μ=3.4μ=3.4 and σ=1.16σ=1.16. Explain how you know the shape the distribution takes on.