<h2>
Answer with explanation:</h2>
Let
be the population mean.
By considering the given information , we have
Null hypothesis : 
Alternative hypothesis : 
Since alternative hypothesis is right-tailed , so the test is a right-tailed test.
Given : Sample size : n=16 , which is a small sample , so we use t-test.
Sample mean:
;
Standard deviation: 
Test statistic for population mean:

i.e. 
Using the standard normal distribution table of t , we have
Critical value for
: 
Since , the absolute value of t (2.333) is smaller than the critical value of t (2.602) , it means we do not have sufficient evidence to reject the null hypothesis.
Hence, we conclude that we do not have enough evidence to support the claim that answering questions while studying produce significantly higher exam scores.
Answer:
-4
Step-by-step explanation:
let n be least.
3n-12=4(n+n+2)
3n-12=8n+8
3n-8n=8+12
-5 n=20
n=-4
Answer:
The total money made by Grace is $477.
Step-by-step explanation:
Given:
Charge per hour for mowing lawn = $6
Charge per hour for pulling weeds = $11
Number of hours for which lawns are mowed = 63 hours
Number of hours for which weeds are pulled = 9 hours
Now, total money made by Grace in September can be calculated by adding the total money gained in mowing lawns and pulling weeds.
Total money gained in mowing lawns is given as:

Total money gained in pulling weeds is given as:

Now, total money made = 
Therefore, the total money made by Grace is $477.
What does the problem says?