Mary wants to hang a mirror in her room. the mirror and frame must have an area of 7 square feet. the mirror is 2 feet wide and
1 answer:
You might be interested in
Donald earns $23 each weekend and Mickey earns $30.
Step-by-step explanation:
Given,
Money earned by Mickey and Donald = $53
Let,
Share of Mickey = x
Share of Donald = y
According to given statement;
x+y=53 Eqn 1
x = y+7 Eqn 2
Putting value of x from Eqn 2 in Eqn 1
Dividing both sides by 2
Putting y=23 in Eqn 2
Donald earns $23 each weekend and Mickey earns $30.
Keywords: linear equation, substitution method
Learn more about linear equations at:
#LearnwithBrainly
Answer:
Step-by-step explanation:
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The t distribution or Student’s t-distribution is a "probability distribution that is used to estimate population parameters when the sample size is small (n<30) or when the population variance is unknown".
The shape of the t distribution is determined by its degrees of freedom and when the degrees of freedom increase the t distirbution becomes a normal distribution approximately.
Data given
Confidence =0.99 or 99%
represent the significance level
n =16 represent the sample size
We don't know the population deviation
Solution for the problem
For this case since we don't know the population deviation and our sample size is <30 we can't use the normal distribution. We neeed to use on this case the t distribution, first we need to calculate the degrees of freedom given by:
We know that so then
and we can find on the t distribution with 15 degrees of freedom a value that accumulates 0.005 of the area on the left tail. We can use the following excel code to find it:
"=T.INV(0.005;15)" and we got on this case since the distribution is symmetric we know that the other critical value is