For samples of the specified size from the population described, find the mean and standard deviation of the sample mean x. One truck from Lakeland Trucking, Inc. can carry a load of 3880.8 lb. Records show that the weights of boxes that it carries have a mean of 751b and a standard deviation of 141b. For samples of size 49, find the mean and standard deviation of x. A) x= 75; x= 2 B) = 75; 0 = 14 C)μ = 2;0= 75 D) μ= 14; 0 = 75

The data set of size 40 has mean 15 and standard deviation 2. Approximately how many observations lie between 13 and 17?

For questions 6 through 11, refer to the following table, representing responses from the 2018 GSS: Respondent Sex Mean Hours Worked Last Week Standard Deviation N Male 44.60 14.969 670 Female 38.15 13.276 711 6. What proportion of females worked less than 40 hours per week?    a. How many people in the sample does that correspond to?7. What percentage of males worked between 40 and 50 hours per week?    a. How many people in the sample does that correspond to?8. What number of hours worked among females corresponds with a Z score of -2.00?9. Calculate the number of hours worked last week that corresponds to the 95th percentile for each sex.    a. If you were going to calculate the 75th percentile, what Z value would you use? 10. Calculate the standard error for both males and females.    a. What are you using for sigma, and why? 11. Calculate the 95% confidence interval for each sex. Can you say with 95% confidence that they are different? Why or why not?    a. If you were…

A population of N=5 scores has a mean of μ=8. If one score with a value of X=4 is removed from the population, what is the value for the new mean? a. μ=9 b. μ=10 c. μ=8 d. μ=7

In this problem, assume that the distribution of differences is approximately normal. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value by a small amount and therefore produce a slightly more "conservative" answer.Suppose that at five weather stations on Trail Ridge Road in Rocky Mountain National Park, the peak wind gusts (in miles per hour) for January and April are recorded below. Wilderness District 1 2 3 4 5 January 128 139 129 64 78 April 115 104 115 88 61 Does this information indicate that the peak wind gusts are higher in January than in April? Use α = 0.01. Solve the problem using the critical region method of testing. (Let d = January − April. Round your answers to three decimal places.) test statistic =   critical value =

A variable is normally distributed with mean 15 and standard deviation 3. Use your graphing calculator to find each of the following areas. Write your answers in decimal form. Round to the nearest thousandth as needed. a) Find the area to the left of 14. b) Find the area to the left of 12. c) Find the area to the right of 13. d) Find the area to the right of 16. e) Find the area between 12 and 25. Question Help: D Post to forum Calculator Submit Question

Suppose that 50 measurements were taken and the mean was calculated to be 4.55. Assume next that one of the data items was 19.4This was assumed to be an outlier as was discarded. What would be the mean of the remaining 49 numbers? I

Analyze the following data. Assume the true value of L (the length of a table) is 93.40cm. L(cm) 93.2 93.3 93.9 92.8 93.5 93.4 92.9 a) What are the mean and standard deviation of this data sample? b) What is the uncertainty of the mean? c) Report the measured value of L. d) What is the relative discrepancy between the measured value of L and its true value? Suppose you have a second set of data for the same quantity that gives the following result: L = (93.90 ± 0.02) cm. e) Is this value more or less precise than the first value? f) Is this value more or less accurate than the first value? g) Do the two values agree given their uncertainties? h) What is the relative discrepancy between the two values?

3. In a normal frequency distribution of serum sodium concentrations, the mean is 141 mEq/L and the standard deviation is 3.2 mEq/L. Which of the following most closely represents the percentage of values in the interval between 137.8 mEq/L and 144.2 mEq/L? OA) 25% B) 50% C) 65% OD) 95% OE) 99% 456

Suppose the measurement of 800 items are normally distributed with mean 66 cm and standard deviation 5 cm,  the number of items with measures 72 cm or more is   A. 702 B. 708 C. 92 D. 98