Note :- If sample size n > 30 OR Population standard deviation σ is given then We use Z test.
If sample size n < 30 AND Population standard deviation σ is unknown then we use t test.
In this question we are not given Population standard deviations σ1 and σ2.
Also n1 = 14 and n2 = 13 both sample sizes are LESS than 30.
Therefore we use t test.
Given :- Assume the population standard deviations are equal. ( σ1 = σ2)
then Degrees of freedom = n1 + n2 - 2 = 14 + 13 - 2 = 25.
(kindly find the image attached with this solution)
Answer :- Therefore 25 degrees of freedom are used to find the t critical value.
Answer:
78 mg
Step-by-step explanation:
370 mg - 110 mg = 260 mg (amount decayed in the 8 total years)
260 mg ÷ 8 years = 32.5 mg decayed per year
32.5 × 9 years (years between 2008 and 2017) = 292.5 mg
370 mg - 292.5 mg = 77.5 mg, rounded to 78 mg
Answer:
101 meter
Step-by-step explanation:
I think
Answer: 25x² - 64
<u>Step-by-step explanation:</u>
(5x + 8)(5x - 8)
= 5x(5x - 8) + 8(5x - 8)
= 25x² - 40x + 40x - 64
= 25x² + 0x - 64
= 
NOTE: descending powers means the biggest exponent goes first, then the next biggest exponent, etc.
For example: x⁴ then x³ then x² then x then the number (which is actually x⁰)
Answer:
sin(4)
Step-by-step explanation:
sin(-184) is the equivalent to sin(4) (degree), positive and acute angle.
