# Multiple choice

#### AlexKom

##### New Member
Hello,
I have some questions:

A researcher wants to determine the mean income of adults in a particular state. She decides to tae a random sample of 1525 citizens with a driver's license. Which of the foollowing statements is not correct?

A) People without a license will be missed in the sample
B0 People from another state wil not be included
C) The mean income of the sample will be reasonably close to the mean of the population
D)It is likely that most people of driving age will be included.
E) The sample standard deviation will be simolar in value to the actual standard deviation.

I think that C is the right answer. Is it correct?

Thank you

#### JohnM

##### TS Contributor
It's either C or E, but their wording is "vague" enough to make it uncertain.

#### AlexKom

##### New Member
Help

I have one more question:
A dice game pays a player $5 for rolling a 3 or a 5 with a single die. The player has to pay$2 for any other roll. If a person players the game 30 times, what is the probability that the person will win at least $15. I am sorry, I don't understand how to do it at all. Can you please give me a hint? #### Soma Dasgupta ##### New Member AlexKom said: Hello, I have some questions: A researcher wants to determine the mean income of adults in a particular state. She decides to tae a random sample of 1525 citizens with a driver's license. Which of the foollowing statements is not correct? A) People without a license will be missed in the sample B0 People from another state wil not be included C) The mean income of the sample will be reasonably close to the mean of the population D)It is likely that most people of driving age will be included. E) The sample standard deviation will be simolar in value to the actual standard deviation. I think that C is the right answer. Is it correct? Thank you Options C and E are incorrect. The sample of citizens with driver's licenses is not representative. Hence the sample mean xannot come close to the mean of the required population mean. In the same manner the sample std deviation will not be close to the required population std deviation. #### JohnM ##### TS Contributor AlexKom said: I have one more question: A dice game pays a player$5 for rolling a 3 or a 5 with a single die. The player has to pay $2 for any other roll. If a person players the game 30 times, what is the probability that the person will win at least$15.

I am sorry, I don't understand how to do it at all. Can you please give me a hint?
There is a 1/3 probability of winning $5, and a 2/3 probability of losing$2 - use this info to find the expected value (mean) of the probability distribution, and the variance / standard deviation.

Now that you have the mean and standard deviation, you can use the normal approximation to the binomial to figure out the probability of winning \$15 or more when you play 30 times.