Sam works at the JJ Electronics Factory. JJ produces the A23 electronic component. The length, X, of an A23, is normally distributed with a mean μ= 10 centimeters and a standard deviation o = 0.53 centimeters. Sam randomly selects 20 A23 components from the production line for quality control purposes and measures their lengths. Let M be the sample mean length of the measured A23 components. Let S be the total length of the measured A23 components. (i.e. sum of the 20 lengths. a) What is the probability that X < 10.5? .6915 b) What is the probability that X > 10.5? .3085 c) What is the probability that all of the 20 measurements are less than 11? .0171 d) What is the expected value of S? 200

let x be a ramdom variable with mean= 150 and standard deviation =4.2. Ramdom samples of fixed size n=30 are drawn from the distribution of x. determine the distribution, mean, and standard deviation of sample mean

Assume that you have been provided the following information for a sample of cars The covariance between weight and miles per gallon is equal to -4.9 pound-miles. The standard deviation of the cars' mileages is 7.75. The standard deviation of the cars' weights is 0.94. Estimate the correlation coefficient to the first decimal place.

A population has a mean μ=139 and a standard deviation σ=24. Find the mean and standard deviation of the sampling distribution of sample means with sample size n=48.

Calculate the test statistic (t) and p-value.

A researcher collects data that represents the average number of hours of sleep in the last two nights by 8 depressed patients and 9 non-depressed patients. The researcher is interested in whether the two groups reliably differ in the amount of sleep they get.     Use Jamovi to calculate t-obt and the p value.

A manufacturing company produces bearings. One line of bearings is specified to be 1.64 centimeters (cm) in diameter. A major customer requires that the variance of the bearings be no more than .001 cm². The producer is required to test the bearings before they are shipped, and so the diameters of 16 bearings are measured with a precise instrument, resulting in the following values. Assume bearing diameters are normally distributed. Use the data and a = 0.01 to test to determine whether the population of these bearings is to be rejected because of too high a variance. 1.68 1.62 1.63 1.70 1.66 1.63 1.65 1.71 1.64 1.69 1.57 1.64 1.59 1.66 1.63 1.65 Appendix A Statistical Tables (Round your answer to 2 decimal places, e.g. 15.25.) The value of the test statistic is and we reject the null hypothesis ⇒

An experiment was conducted to determine whether giving candy to dining parties resulted in greater tips. The mean tip percentages and standard deviations are given in the accompanying table along with the sample sizes. Assume that the two samples are independent simple random samples selected from normally distributed​ populations, and do not assume that the population standard deviations are equal. Complete parts​ (a) and​ (b).   ...   Question content area top right Part 1     μ n x s   No candy μ1 36 18.61 1.39 Two candies μ2 36 21.26 2.34   * find the t stat * find the p value * State the conclusion * Construct a confidence interval suitable for testing the claim that the two samples are from populations with the same mean.