Two samples, one of size 30 and the second of size 29, are selected to test the difference between two independent population means. How many degrees of freedom are used to find the critical value? Assume the population standard deviations are unknown but equal.   Multiple Choice   59   58   57   30

Use the Empirical Rule. The mean speed of a sample of vehicles along a stretch of highway is 71 miles per​ hour, with a standard deviation of 5 miles per hour. Estimate the percent of vehicles whose speeds are between 61 miles per hour and 81 miles per hour.​ (Assume the data set has a​ bell-shaped distribution.)   Approximately ________ ​% of vehicles travel between 61 miles per hour and 81 miles per hour.

Use the sample data set to evaluate each of the steps in determining the sample standard deviation   23 20 14 35 28 Give an exact answer, not an approximation, for each step except the standard deviation. round the standard deviation to the nearest hundredth..  =   =  variance, s2 =  standard deviation, s =

Two stores sell watermelons. At the first store the melons weigh an average of 22 pounds, with a standard deviation of 2.5 pounds. At the second store the melons are smaller. with a mean of 18 pounds and a standard deviation of 2 pounds. You take and SRS of 40 melons from the first store and SRS of 34 from the second store Find the mean of each sampling distribution

Find the range, vanance, and standard deviation for the given sample data. Include appropriate units in the results. Listed below are the measured radiation absorption rates (in Wikg) corresponding to various cell phone models. If one of each model is measured for radiation and the results are used to find the measures of variation, are the results typical of the population of cell phones that are in use? 1.16 0.82 0.51 0.69 1.11 0.82 0.69 0.75 0.52 0.53 1.34

The director of research and development is testing a new medicine. She wants to know if there is evidence at the 0.02 level that the medicine relieves pain in more than 346 seconds. For a sample of 58 patients, the mean time in which the medicine relieved pain was 352 seconds. Assume the population standard deviation is 23. Find the P-value of the test statistic. 囲 Tables E Keypad Keyboard Shortcuts 0.0582 %3D IX

A sample of 100 clients of an exercise facility was selected. Let X = the number of days per week that a randomly selected client uses the exercise facility. Frequency 2 1 15 30 3 27 4 10 8 6. 8 Find the 80th percentile.

Use the magnitudes​ (Richter scale) of the 120 earthquakes listed in the accompanying data table. Use technology to find the​ range, variance, and standard deviation. If another​ value, 8.00​, is added to those listed in the data​ set, do the measures of variation change​ much?  3.30 2.77 2.80 1.96 1.69 2.54   2.43 3.44 3.92 1.58 2.87 1.63   2.56 3.95 2.50 2.44 1.82 2.19   2.44 2.99 2.92 2.35 1.98 3.06   2.78 3.86 2.95 2.07 1.86 2.36   2.37 3.46 3.45 1.54 2.54 1.49   2.22 3.06 2.27 3.20 1.96 1.91   2.40 2.95 2.61 1.49 2.16 2.33   1.91 2.70 2.92 1.80 3.66 2.69   1.43 3.60 3.13 2.56 1.54 1.41   2.83 2.85 2.20 1.68 3.18 1.38   1.73 2.37 1.15 2.35 2.46 1.81   2.01 3.00 1.94 2.42 1.85 2.24   2.35 3.22 3.97 2.10 1.48 2.31   2.31 2.62 2.55 2.20 2.77 2.46   2.69 3.57 2.84 2.75 3.26 1.74   4.72 3.23 2.36 2.00 3.83 2.41   2.88 2.67 2.32 2.80 2.80 2.40   3.41 2.34 1.49 2.41 2.45 2.50   2.73 2.44 2.78 2.65 2.68 2.43 Without the extra data​ value, the range is 3.573.57. ​(Type an integer or…

An insurance company crashed four cars in succession at 5 miles per hour. The cost of repair for each of the four crashes was $412, $451, $417, $232 O. Compute the range, sample variance, and sample standard deviation cost of repair. The range is $ s? = dollars? (Round to the nearest whole number as needed.) s=S S= $ (Round to two decimal places as needed.)

Analysts of traffic control systems believe that the average speed of heavy vehicles on highways has decreased after passing an ordinance of high penalty to regulate over speeding. The average speed for a random selection of 36 trucks was found to be 55 mph with a standard deviation of 5 mph. The speed before the ordinance was passed was an average of up to 57 mph on these highways.Compute the value of the test statistic. Group of answer choices 0.40 -0.40 2.40 -5.37 -2.40