upload week01 assignments

materials/tutorial_01/tutorial_01.ipynb

@@ -786,7 +786,7 @@
     "editable": false,
     "nbgrader": {
      "cell_type": "markdown",
-     "checksum": "de454a984c336bda59306f3c18cff039",
+     "checksum": "2fcde972508af5f8852856dd7a253a06",
      "grade": false,
      "grade_id": "cell-b71652c72a001c12",
      "locked": true,
@@ -799,7 +799,7 @@
     "**Question 1.8**\n",
     "<br>{points: 1}\n",
     "\n",
-    "a) In one or two sentences, explain why a Bonferroni correction is needed to assess the significance of the pairwise the test performed in **Question 1.7**.\n",
+    "a) In one or two sentences, explain why a Bonferroni correction is needed to assess the significance of the pairwise test performed in **Question 1.7**.\n",
     "\n",
     "b) In one or two sentences, explain how to implement a Bonferroni correction in this case."
    ]

materials/worksheet_01/tests_worksheet_01.R

@@ -367,7 +367,7 @@ test_2.6 <- function() {
 
   answer_hash <- digest(tolower(answer2.6))
   test_that("Solution is incorrect", {
-    expect_equal(answer_hash, "d110f00cfb1b248e835137025804a23b")
+    expect_equal(answer_hash, "6e7a8c1c098e8817e3df3fd1b21149d1")
   })
 
   print("Success!")

materials/worksheet_01/worksheet_01.ipynb

@@ -979,7 +979,7 @@
     "editable": false,
     "nbgrader": {
      "cell_type": "markdown",
-     "checksum": "07fe636f2be5479c6df1f9c2cd3b2239",
+     "checksum": "b1bff46d89ba37a50486ffca96dfba13",
      "grade": false,
      "grade_id": "cell-dcbb5b6b07f92841",
      "locked": true,
@@ -996,13 +996,13 @@
     "\n",
     "**A.** The current ad's sample median and sample mean are higher than those of the new ad. Moreover, both data spreads are quite similar.\n",
     "\n",
-    "**C.** The new ad's sample median and sample mean are statistically significantly higher than those of the current ad. \n",
+    "**B.** The new ad's sample median and sample mean are statistically significantly higher than those of the current ad. \n",
     "\n",
-    "**D.** The new ad's population median and population mean seems to be higher than those of the current ad. However, there's the possibility that the observed difference is due to sampling variability. Both data spreads are quite similar.\n",
+    "**C.** The new ad's population median and population mean seems to be higher than those of the current ad. However, there's the possibility that the observed difference is due to sampling variability. Both data spreads are quite similar.\n",
     "\n",
-    "**E.** The new ad's population median and population mean are higher than those of the current ad. Moreover, the data spreads are quite different by treatment.\n",
+    "**D.** The new ad's population median and population mean are higher than those of the current ad. Moreover, the data spreads are quite different by treatment.\n",
     "\n",
-    "*Assign your answer to an object called `answer2.6`. Your answer should be one of `\"A\"`, `\"B\"`, `\"C\"`, `\"D\"`, or `\"E\"` surrounded by quotes.*"
+    "*Assign your answer to an object called `answer2.6`. Your answer should be one of `\"A\"`, `\"B\"`, `\"C\"`, or `\"D\"` surrounded by quotes.*"
    ]
   },
   {
@@ -1063,7 +1063,7 @@
     "\n",
     "**In other words, is the observed difference statistically significant?** \n",
     "\n",
-    "Recall the 2-sample $t$-test that you've learned in STAT 201 to test the hypotheses stated in **Questions 2.0** and **2.1**. The test statistic to conduct this test (with unequal population variances) is defined as:\n",
+    "Recall the 2-sample $t$-test that you've learned in STAT 201 to test the hypotheses stated in **Questions 2.0** and **2.1**. The test statistic to conduct this test (with **unequal population variances**) is defined as:\n",
     "\n",
     "$$\n",
     "T = \\frac{\\bar{x}_{\\text{new}} - \\bar{x}_{\\text{current}}}{\\sqrt{\\frac{s^2_{\\text{new}}}{n_{\\text{new}}}+\\frac{s^2_{\\text{current}}}{n_{\\text{current}}}}}\n",
@@ -1086,7 +1086,7 @@
     "\n",
     "- Note: if we assume equal variances, the pooled SD is used as a denominator of $T$ and $\\text{df} = n_\\text{new} + n_\\text{current} -2$\n",
     "\n",
-    "Use the corresponding `R` function to calculate all these values. Make sure to use `broom::tidy()` to get a more organized result.\n",
+    "Use the corresponding `R` function to calculate all these values (i.e. compute 2-sample t-test). Make sure to use `broom::tidy()` to get a more organized result.\n",
     "\n",
     "*Fill out those parts indicated with `...`, uncomment the corresponding code in the cell below, and run it. Assign your answer to an object called `answer2.7`.*"
    ]
@@ -1855,7 +1855,7 @@
    "mimetype": "text/x-r-source",
    "name": "R",
    "pygments_lexer": "r",
-   "version": "4.2.3"
+   "version": "4.2.2"
   }
  },
  "nbformat": 4,