Answer:
The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 24 - 1 = 23
98% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 23 degrees of freedom(y-axis) and a confidence level of
. So we have T = 2.5
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 42 - 1.02 = $40.98.
The upper end of the interval is the sample mean added to M. So it is 42 + 1.02 = $43.02.
The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.
Answer:
D. c/7
Step-by-step explanation:
An algebraic expression refers to the equation. In the question, it says to divide a number (c) by seven, giving you c/7

The answer=>
For this,we need to know what's Middle splitting method
- In order to factorize x² + bx + c we have to find numbers p and q such that p + q = b and pq = c. After finding p and q, we split the middle term in the quadratic as <em><u>px + qx and</u></em> get desired factors by grouping the terms.
Step-by-step explanation:

i.e
Alpha= Beta = 4
20+0.15x = 35+0.10x
0.15x=15+0.10x
0.05x=15
x= 15/0.05
x= 300minutes
check:
300*.015 = 45+20=65
300*0.10 = 30 + 35 = 65
they equal
so number of minutes would be 300
Answer:
D
Step-by-step explanation: