Statistics and Probability Answers

A sample size of 400 is taken from a population x with a u=4 and o=2.Find the probability that the sample mean is less than 3.85

Suppose that we will take a random sample of size n from a population having mean u and standard deviation o. For each of

the following situations, find the mean, variance, and standard deviation of the sampling distribution of the sample mean X:

a. μ = 10, o=2, n = 25

b. μ=500, o=.5, n = 100

C. μ=3, o =., n=4

d. μ= 100, o=1, n = 1,600

What will I do here if the mean and stdv is already given? TT sorry I am confused

If Scores are normally distributed with a mean of 30 and a standard deviation of 5. What percent score is.

a.) Equal or greater than 30?

b.) Equal or greater than 37?

c.) From 28 to 34?

The average height of 12 children is 124.7 with a standard deviation of 7.5. Assuming

that the heights are normally distributed, what percent of the students have a height of

132.2 and longer?

X-N(45, variance) and p(x>51)=0.288 find standard deviation

Assuming that the samples come from normal distributions, find the margin of error E given the following.

2. n=150, x-=98, s=9.90, 95% confidence.

3. n=350, x-=125, s=11.18, 99% confidence.

4. n=500, x-=236, s=15.36, 90% confidence.

5. n=785, x-=459, s=21.42, 99% confidence.

Members of the urban poor receive an average of ₱110 per day with a standard deviation of ₱20. If a random sample of 25 people is taken, what is the approximate mean of the sampling distribution?

Members of the urban poor receive an average of ₱110 per day with a standard deviation of ₱20. If a random sample of 25 people is taken, what is the approximate mean of the sampling distribution?

Members of the urban poor receive an average of ₱110 per day with a standard deviation of ₱20. If a random sample of 25 people is taken, what is the approximate mean of the sampling distribution?

a school administrator claims that less than 50% of the students of the school are dissatisfied by the community cafeteria service. Test this claim by using sample data obtained from a survey of 500 students of the school where 54% indicated their dissatisfaction of the community cafeteria service. use a 0.05