Flashcard Lesson 6.4 ~6.6

Front

When can you use a normal approximation for the sampling distribution of p?

Back

You can use a normal approximation when np ≥ 10 and n(1-p) ≥ 10.

Front

What is the probability of getting a sample of size 50 that has 15 or more students who believe Monday will be a snow day if 28% of all students believe it?

Back

The probability is 0.376.

Front

What is the average amount of sleep teenagers attending public high schools get each night?

Back

The average is 5.7 hours.

Front

What is the standard deviation of sleep for teenagers attending public high schools?

Back

The standard deviation is 1.7 hours.

Front

What is the probability that a randomly selected group of 35 high school students get more than 6 hours of sleep each night?

Back

The probability is 0.148.

Front

For the population of farm workers in New Zealand, what is the mean weekly income?

Back

The mean weekly income is $500.

Front

What is the standard deviation of weekly income for farm workers in New Zealand?

Back

The standard deviation is $160.

Front

What is the probability that a randomly selected worker has an income of at most $530?

Back

The probability is 0.9696.

Front

What does the symbol p̂ represent?

Back

p̂ represents the sample proportion.

Front

What is the formula for the standard error of the sample proportion?

Back

The formula is SE = sqrt[(p(1-p)/n)].