Answer:
Mean track length for this rock specimen is between 10.463 and 13.537
Step-by-step explanation:
99% confidence interval for the mean track length for rock specimen can be calculated using the formula:
M±
where
- M is the average track length (12 μm) in the report
- t is the two tailed t-score in 99% confidence interval (2.977)
- s is the standard deviation of track lengths in the report (2 μm)
- N is the total number of tracks (15)
putting these numbers in the formula, we get confidence interval in 99% confidence as:
12±
=12±1.537
Therefore, mean track length for this rock specimen is between 10.463 and 13.537
Answer:
180
Step-by-step explanation:
20 x 9 = 180
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Answer:
Hi there!
Your answer is:
A. Chemical change
Step-by-step explanation:
Chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances.
Total number of coins in question = 275
Number of quarters among the total coins = 120
Then
Remaining number of coins = 275 - 120
= 155
Percentage of coins that are nickel = 20%
Then
Number of coins that are nickel = (20/100) * 155
= 155/5
= 31
Remaining number of coins = 155 - 31
= 124
Ratio of dimes to pennies = 1:3
Let us assume the common ratio to be = x
Then
x + 3x = 124
4x = 124
x = 124/4
= 31
So
The number of pennies = 3 * 31
= 93
From the above deduction we can conclude that there are 93 pennies. The correct option among all the options given in the question is option "C".
