to generate 120 scores from the normal distribution with mean 75 and standard deviation 8. Determine the number of scores x such that 67≤x ≤83.

In a random sample of ten cell phones, the mean full retail price was $554.00 and the standard deviation was $167.00. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 95% confidence interval for the population mean u. Interpret the results. Identify the margin of error. (Round to one decimal place as needed.)

For the residents in 2014, use R to calculate the interval with 99% certainty that the interval contains the actual population mean of the residents by census tracts. Type in the interval with keyboard. We also know that in each year, the number of residents by census tract in the State of Maryland follows a normal distribution, and the variance in the number of residents within the State of Maryland is the same for different years.  POP2014: 3072, 1989, 3794, 2689, 3211, 3722, 4385, 4009, 7598, 3862, 3097, 2726, 4881, 4157, 2570, 2512, 2518, 4863, 4147, 7139, 6067, 6819, 3705, 3239, 3824, 4977, 2576, 2940, 9791, 5231, 5634, 5337, 4205, 3888, 5562, 3335, 3770, 1808, 2045, 1532, 5420, 4993, 6109, 4377, 5424, 4976, 4507, 3738, 2827, 3485, 1559, 5199, 4702, 3971, 3803, 3356, 4670, 3816, 5477, 4760, 3126, 3630, 3755, 3795, 2578, 3382, 4005, 2442, 6096, 3799, 3843, 3836, 6046, 6431, 3561, 3142, 4829, 5058, 2471, 6119, 3523, 3094, 3146, 3356, 2618, 2366, 4266, 4016, 6080, 1554, 6878, 3645,…

A manufacturer of phone batteries determines that the average length of talk time for one of its batteries is 470 minutes.  Suppose that the standard deviation is known to be 32 minutes and that the data are approximately bell-shaped. Estimate the percentage of batteries whose talk time is between 406 minutes and 534 minutes. Estimate the percentage of batteries whose talk time is less than 438 minutes. Estimate the percentage of batteries whose talk time is more than 534 minutes. answer in excel

Assume that IQ scores are normally distributed, with a mean of 100 points and a standard deviation of 14 points. If 50 people are chosen at random, what is the probability that the sample mean of IQ scores will be between 98 and 102?P(98 ≤ x ≤ 102) = ?

The number of books sold over the course of the for day book fair were 195, 158, 263 and 100.  Assume that samples of  size 2 are randomly selected with replacement from this population of four values.  List the different possible samples and find the mean of each of them.