Answer:
The critical t values are -1.746 and 1.746.
Step-by-step explanation:
Given information:
The weight of a USB flash drive is 30 grams and is normally distributed.
Population mean = 30
Sample size = 17
Sample mean= 31.9
Standard deviation = 1.8
Significance level, α=0.10
Null hypothesis: 
Alternative hypothesis: 
It is a two tailed test.
The t-critical values for a two-tailed test, for a significance level of α=0.1 are -1.746 and 1.746.
Therefore the critical t values are -1.746 and 1.746.
Answer:
13
Step-by-step explanation:
When we subtract a negative, it is like adding
9 - -4
9 +4
13
So the rounded weights would be 3, 5, 2, 6, and 11, as when you round, you look at the number to the right of the one you want to round to. If it's 5 or larger, you add one to the spot you're rounding to, and make the rest of the numbers after into zeroes. If it's below 5, just change the ones after the one you want to round to into zeroes and don't add one.
Then for the estimating of the weight, you would add them together. 3+5+2+6+11. That would equal 27, so the estimate weight is 27 grams.