Answer:
a: z = -1.936
b: 0.0265
d: z < -1.645
Reject H0 if z < -1.645
Step-by-step explanation:
We are given:
H0: µ = 20
HA: µ < 20
n = 60, sample mean: 19.6, σ = 1.6
Since the alternate hypothesis has a < sign in it, it is a left tailed test. The < or > sign in the alternate hypothesis points towards the rejection region.
For a: We need to calculate the test statistic for our situation. This is done with a z-score formula for samples.
For b: we need to use the z-score table to look up the p-value for the score we calculate in part a. The p-value is 0.0265. This means that there is only about a 2.65% chance that the sample values were a result of random chance.
For d: Since the significance level is 0.05, and this is a one tailed test, we have a critical value of z < - 1.645. This means that if the z-score we calculate in part a is less than -1.645, we will reject the null hypothesis
See attached photo for all the calculations!
Answer:
$145.00
Step-by-step explanation:
Since w is the number of weeks, substitute the w in (25+8w) with 15
y = 25 + 8(15)
y = 25 + 120
y = 145
The student saved $145.00 after 15 weeks
Answer:
18 and 19
Step-by-step explanation:
Consecutive positive integers have a difference of 1 between them
let n and n + 1 be the 2 integers, then
n(n + 1) = 342, that is
n² + n = 342 ( subtract 342 from both sides )
n² + n - 342 = 0 ← quadratic equation in standard form
(n + 19)(n - 18) = 0 ← in factored form
Equate each factor to zero and solve for n
n + 19 = 0 ⇒ n = - 19
n - 18 = 0 ⇒ n = 18
However, n > 0 ⇒ n = 18 and n + 1 = 18 + 1 = 19
The 2 integers are 18 and 19
To find the answer, we can use the Pythagoras theorem, where:
Where a and b is the side length and c is the diagonal.
In this case:
Therefore, the answer is 79.2cm
Hope it helps!
A correlation between 2 variables does not imply causation.