Question

A polling organization took a random sample of 2,500 single parents to determine how many single parents have two jobs. Suppose 38% of all single parents have two jobs. If the total population of single parents is 12 million, is the 10% condition met? Justify your answer.

Yes, 0.10(2,500) = 250, which is less than the total population. Yes, 10(2,500) = 25,000, which is less than the total population. No, 0.10(12,000,000) = 1,200,000, which is more than the sample. No, 10(12,000,000) = 120,000,000, which is more than the sample. There is not enough information to determine whether the 10% condition is met.

5. The Lakeland Post polled 1,231 adults in the city to determine whether they wash their hair before their body while in the shower. Of the respondents, 63% said they washed their hair first. Suppose 51% of all adults actually wash their hair first. What are the mean and standard deviation of the sampling distribution?

The mean is 0.51 and the standard deviation is 0.0142. The mean is 0.51 and the standard deviation is 0.0138. The mean is 0.63 and the standard deviation is 0.0226. The mean is 0.63 and the standard deviation is 0.0138. The mean is 0.63 and the standard deviation is 0.0142.

Answer 1

One of the condition is as

The population is at least 10 times as large as the sample.

here 10*n = 10* 2500 = 25000 < 12000000

So correct option is as "Yes, 10(2,500) = 25,000, which is less than the total population."

5. The Lakeland Post polled 1,231 adults in the city to determine whether they wash their hair before their body while in the shower. Of the respondents, 63% said they washed their hair first. Suppose 51% of all adults actually wash their hair first. What are the mean and standard deviation of the sampling distribution?

Sampling distribution of sample proportion ( ) is approximately normal for large n with mean and standard deviations are as

mean = p = 0.51

for finding standard deviation we need to use p = 0.51

So correct choice is "The mean is 0.51 and the standard deviation is 0.0142"