Answer:
b. Kathy
Step-by-step explanation:
We compare each of their score by how far away from the mean when in term of the standard deviation. Using the following formula

For John he is (85 - 75)/5 = 2.
For Kathy she is (80 - 50)/10 = 3.
Since Kathy is 3 standard deviation better than her class' average, while John is only 2's. We conclude that Kathy did better.
Answer:
(a) 0.0128 to 4 decimal places
(b) The 90% confidence interval is 119.1 < μ < 121.0 to 1 decimal places
Step-by-step explanation:
See the attached documents and graphs. Cheers!
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Answer
7.5 pounds
Step-by-step explanation:
Since adding x grams of salt will bring th percentage of the salt to 25
Hence. 10% of the 50 gram gives. 5 gram initial salt before it is added.
5+ x/ 50 * 100= 25/
5+x /50 = 0.25
5+x = 12.5
X= 12.5- 5
X= 7.5pounds
Answer:
a=31
Step-by-step explanation:
1/2(a-9)=11
a-9=22
a=22+9
a=31