I believe the answer is 0.22
Answer:
we will fail to reject the null hypothesis and conclude that the mean pressure is not different from 4.7 psi
Step-by-step explanation:
Let's first define the hypothesis;
Null hypothesis: H0: μ = 4.7
Alternative hypothesis: Ha: μ ≠ 4.7
We have;
Sample size; n = 110
Sample mean; x¯ = 4.6
Variance: σ² = 0.64
Standard deviation; σ = √0.64 = 0.8
Formula for test statistic is;
z = (x¯ - μ)/(σ/√n)
z = (4.6 - 4.7)/(0.8/√110)
z = -0.1/0.0763
z = -1.31
From online p-value from z-score calculator attached, using; z = -1.31, two tailed hypothesis, significance value of 0.1, we have;
P-value = 0.190196
The p-value is greater than the significance value and thus we will fail to reject the null hypothesis and conclude that the mean pressure is not different from 4.7
σ μ
A way to add fractions that always works is to multiply each numerator by the denominator of the other, then express the sum of products over the product of the denominators.

Here, you have
The sum is -1 1/12
The sum of 2a and 3b:
2a + 3b