Statistics and Probability Answers

Let X denote the number of successes in a series of n independent bernoulli trials with constant probability of success thiter.if kX(n-thiter) os unbaised estimator of thiter(1-thiter), what is the value of k

In a certain​ country, the true probability of a baby being a girl is 0.473. Among the next four randomly selected births in the​ country, what is the probability that at least one of them is a boy​?
The probability is ?. Round to 3 decimal

Assume that there is a ​10% rate of disk drive failure in a year.
a. If all your computer data is stored on a hard disk drive with a copy stored on a second hard disk​ drive, what is the probability that during a​ year, you can avoid catastrophe with at least one working​ drive?
b. If copies of all your computer data are stored on 4 independent hard disk​ drives, what is the probability that during a​ year, you can avoid catastrophe with at least one working​ drive?
a. With two hard disk​ drives, the probability that catastrophe can be avoided is

Assume that females have pulse rates that are normally distributed with a mean mu= 72.0 beats per minute and a standard deviation of alpha =12.5 beats per minute. Complete parts​ (a)
a. If 1 adult female is randomly​ selected, find the probability that her pulse rate is less than 79 beats per minute. Round to four decimal place

find the mean and the standard deviation of the heights of male engineering students in which the heights 66 inches and 75 inches correspond to standard scores of -0.6 and 1.1 respectively

If a chi-square has a probability level greater than .05, is it generally considered significant by traditional social science standards?

you are interested in gathering data from households in cambridge MA. you obtain a phone book and identify a list of households to contact through the phone book. in this example the phone book is an example of what? in answering this question discuss and define the key sampling terms sample population and sampling frame

A simple random sample of 40 items results in a sample mean of 25. The population standard deviation is a=5. The 95% confidence interval of the population mean is
1. (25 ; 1.5495)
2. (23, 4006 ; 26,5993)
3. (23,4505 ; 26,5495)
4. (23,6679 ; 26,3321)
5. (25,5106 ; 27,4591)

When constructing a confidence interval the Z stand normal distribution is used when
1. The sample is given (n>30)
2. The sample variance is given
3. The population variance is given
4. The question is to calculate the 9% confidence interval
5. The level of significance is 1% , 5% or 10%

Consider a population proportion 0.68. The standard error for proportion for n=20 is
1. 0.0109
2. 0.1043
3. 0.2176
4. 0.1404
5. 0.034