Answer:
We accept the null hypothesis and the population mean is $120.
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 100
Sample mean,
= $120
Alpha, α = 0.01
Sample standard deviation, s = $25
First, we design the null and the alternate hypothesis
We use two-tailed t test to perform this hypothesis.
Formula:

Putting all the values, we have
p-value one tail= 0.024
p-value two tail= 0.048
Conclusion:
Since the p-value for two tailed test is greater than the significance level, we fail to reject the null hypothesis and accept it.
Thus, the population mean is $120.
Answer:
$26.91
Step-by-step explanation:
11.96 divided 4 = 2.99
2.99 x 9 = $26.91
Katie is 6; Cathy is 18!
X- Katie’s age now and 3x -Cathys age now
In 6 years, Katie is 12 and Cathy is 24.
2 x (X+6) = 3x + 6
2x + 12 = 3x + 6
6 = x