Answer:
critical value = 1.645
The 90% confidence interval = ( -22.62, -17.58)
Step-by-step explanation:
Given that:
the sample size 
= 178
the sample size 
= 226
the sample mean 
= 54.4
the sample mean 
= 74.5
population standard deviation 
= 18.58
population standard deviation 
= 9.52
level of significance ∝ = 1 - 0.90 = 0.10
The critical value for 
is 1.645
For the construction of our confidence interval, we use 90% since that is used to find the critical value.
∴
The margin of error = 
2.52
The lower limit = 
= ( 54.4-74.5) - (2.52)
= -20.1 - 2.52
= -22.62
The upper limit = 
= ( 54.4-74.5) + (2.52)
= -20.1 + 2.52
= -17.58
The 90% confidence interval = ( -22.62, -17.58)
3 square root of 6*7 - 4 square root of 6*4
Or if it is wrong what are the choices?
Answer:
x+3y = 6
or, x = 6-3y.................(1)
3x+5y =6..........(2)
Substituting x = 6-3y in equation (2),
3 (6 - 3 y)+5 y =6
or, 18 - 9y +5y=6
or, y = 3
x = 6 - 3y = 6- 3.-3 = -3
Answer:
C: 
Step-by-step explanation:
Amplitude is changed by multiplying the entire trig function by a number, by default the amplitude is 1, so multiplying by 6 is necessary; eliminate A and B
Horizontal shift is going through the x axis, so it must be subtracted from the x value. This is only seen in choice C of the remaining answers.
Calculating the period isn't necessary because we already found the right answer but in case you need it in the future; the period is by default 2pi, to get to pi/4, it had to be 8 times smaller, so multiplying x and translations on x by 8 will get you the correct period.
