# stat

posted by .

if the probability of a newborn child being female is 0.5, find the probability that in 100 births, 55 or more will be female.use the normal distribution to approximate the binomial distribution

• stat -

Mean = np = 100 * 0.5 = ?
Standard deviation = √npq = √(100 * 0.5 * 0.5) = ?
Note: q = 1 - p

Finish the calculations, then use z-scores.

z = (x - mean)/sd

Note: x = 55

Determine the probability using the z-score and a z-table.

I hope this will help get you started.

• stat -

.1841

## Similar Questions

1. ### Statistics

Assume that male and female births are equally likely and that the birth of any child does not affect the probability of the gender of any other children. Find the probability of exactly eight in ten births.
2. ### statistik

twenty percent of the employees of a large company are female.use the normal approximation of the binomial probabilities to answer the following question. what is the probability that in a random sample of 80 employeses a)exactly 16 …
3. ### Math

A local motel has 100 rooms. The occupancy rate for the winter months is 60%. Find the probability that in a given winter month more than 65 rooms will be rented. Use the normal distribution to approximate the binomial distribution.
4. ### Statistics

If the probability of a newborn child being female is 0.5, find the probability that in 100 births, 55 or more will be female. Use the normal distribution to approximate the binomial distribution.
5. ### Statistics

Assume it is known that the probability of birth is equal in all months. What is the probability that in the STAT class of 120 students, exactly 20 students have their birthdays in either August or September?
6. ### statistics

Assume a binomial probability distribution has p = .60 and n = 200. a)What are the mean and standard deviation (to 2 decimals)?
7. ### Stats

Use the normal distribution to approximate the following Binomial probability. A product is manufactured in batches of 100 and a defect rate of 8%. Find the probability of more then 7 defects.
8. ### stats

Assume it is known that the probability of birth is equal in all months. What is the probability that in the STAT 1025 class of 120 students, exactly 20 students have their birthdays in either August or September?
9. ### math

Assume it is known that the probability of birth is equal in all months. What is the probability that in the STAT 1025 class of 120 students, exactly 20 students have their birthdays in either August or September?
10. ### math

Assume it is known that the probability of birth is equal in all months. What is the probability that in the STAT 1025 class of 120 students, exactly 20 students have their birthdays in either August or September?

More Similar Questions