# Chapter 1. Conditions for Inference in Practice

true
Stat Tutor
true
true

0:46

### Question 1.1

TLlzMkNXSYk6/lVBIBb78W6jO0u3V+HPFz+zXXk++6GtcbGk/f2I+t6sLGFXK8Rq/GFsDkFLENcaVNm+oqZIEZy0Z1tj3TEpiS6/U4TeZbYUbsb2yjqVwX5B/R4jMaZQoACvftZ9nuw/3pbiY/zqSVtIn61cEqUeMwC6SpGBvxetnYOEIz8ggEGh7T4BA4DeDYT85ofDDqkg0/39fcnZ3/O+dHyQTLcxCl7lNRtTLPIlf8QU8fF7A/UnooGSw7AiQWAuXexsso8H6+GN
Correct. Individuals need to be randomly selected in surveys for inference conclusions to be valid.
Incorrect. Individuals need to be randomly selected in surveys for inference conclusions to be valid.
2
Try again.

### Question 1.2

FspTByd2mSTxr6E65IKC4Tcz/EKOsSBcwHiQwkZ+aqVELgAvlnnDtmlNE6nh75FYZR+Sf4D2j5NtGubGeg0Rm5u0tPqHGkb+szpsHL/JzN6Szb5oI1HS+QlDaYFBobCOnGJ2Mi8+mQl9TyhamevLxEdyxj5eIIp9G8fZTujSOoCgQuV4/CKXQwK3HzMDKRlNi0hOs+8bYoDtPcAnJB8jjTdtJYFtS4tHH7u8+CE4MSAAOySzqlvy1jUHU3or47xaBSF5fTj87we1BenG
Correct. Individuals need to be randomly allocated to treatments in experiments for inference conclusions to be valid.
Incorrect. Individuals need to be randomly allocated to treatments in experiments for inference conclusions to be valid.
2
Try again.

1:02

### Question 1.3

hUTvrMYxlDEquhy4DkOrfLhCJvbqfqcv941P1nLGjIIPsurKULhaLt/x6xy1v/iRaeW52vKQcgbTD5U0cwjlEvnDt1rgja8DW4xz+Sz6k5UdXX4XOuzwMGBXPuqBJl5xMZVjrnG7AUjQqUKY
Correct. No matter how fancy or elaborate the data analysis, without proper data collection the results may be invalid.
Incorrect. No matter how fancy or elaborate the data analysis, without proper data collection the results may be invalid.
2
Try again.

1:40

### Question 1.4

Correct. Data were collected with a call-in opinion poll during a nightly news cast.
Incorrect. Data were collected with a call-in opinion poll during a nightly news cast.
2
Try again.

3:09

### Question 1.5

tG8y/ZEVobK1kMWLFXnWR+iTGXHK0HIZvpD2jaxTfUhIYVmqDfSb726WCy57dwYAnSIzrjtHCJ0LfBPgsHHMSHmLP6y/TgHJlDVx5d8dWdm73Sx7NKaNW7hfZuMrr4kQSbaGFAPWtijUV48FBZzMKdXakyD/9bLrBIob6TlELoACDvRFUNDmPovSgwFLP6N7yJxyg0vn5S1KjNK+i8uLD0G+iZcN0kDysR/w1aBepjlUI4dhJnTTDSaloQ0XUWZB7vTKfCasUKJB0euCzzI9I+VL4JCZ1C4O+ZzVS/LIFiMg/y8IAVyJVAPkkBV6cPT7x/olwVPsRnHtbjR3+V0JaqUmopg6BJKuxrgKhzqnPuDibq89Ed0z9QgeX5hn1h9U
Correct. All of these are consequences of lack of randomization.
Incorrect. All of these are consequences of lack of randomization.
2
Try again.

4:13

### Question 1.6

e78uiHaUj1q1/mIcUvy4iKlQzMqp9T87cOHIA/V/1S6aPsSDdsWFZfoxXndq6Jy4swumsW5FkBDd7JC4HDjG2Lt4jTZsx2Wy3b3/UphyqxZX6PwRP057BzWtopmMjPFb4veBFLkb5ogqct+D2ukL8qB1qfIVED18+J0XD6wXzedj8b4zf4U2HzcQuZHWGyGllMrtq2ykR32Bv/fokeKxOcTZhqOzQkvGWEL7YW04r+eeAR3QizMj9S4mIHMLqv91qrZyORzcJ0BhEEPF64hDLjM88a8S8KieF2IxrQ==
Correct. Since outliers are usually problematic, always plot your data and check for outliers.
Incorrect. Since outliers are usually problematic, always plot your data and check for outliers.
2
Try again.

4:57

### Question 1.7

QG+D3zRI5lu+VWC4+o16QThW0nXQZm+zZOWE6sycBM0zgH7kaBKtizfhf/HBlrVPdr5tRUtF3wQMHltEdoCWXSM+zHTXCCGSPMHXok03U4C16/AB0SYKSixMhBlaFiswK0ugGU4PDus=
Correct. If a condition required for an inferential procedure is not met, the results may be invalid.
Incorrect. If a condition required for an inferential procedure is not met, the results may be invalid.
2
Try again.